#include "mongoose.h"
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_internal.h"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#ifndef CS_MONGOOSE_SRC_INTERNAL_H_
#define CS_MONGOOSE_SRC_INTERNAL_H_

 /* Amalgamated: #include "common/mg_mem.h" */

#ifndef MBUF_REALLOC
#define MBUF_REALLOC MG_REALLOC
#endif

#ifndef MBUF_FREE
#define MBUF_FREE MG_FREE
#endif

#define MG_SET_PTRPTR(_ptr, _v) \
  do {                          \
    if (_ptr) *(_ptr) = _v;     \
  } while (0)

#ifndef MG_INTERNAL
#define MG_INTERNAL static
#endif

#ifdef PICOTCP
#define NO_LIBC
#define MG_DISABLE_PFS
#endif

/* Amalgamated: #include "common/cs_dbg.h" */
/* Amalgamated: #include "mg_http.h" */
/* Amalgamated: #include "mg_net.h" */

#ifndef MG_CTL_MSG_MESSAGE_SIZE
#define MG_CTL_MSG_MESSAGE_SIZE 8192
#endif

/* internals that need to be accessible in unit tests */
MG_INTERNAL struct mg_connection *mg_do_connect(struct mg_connection *nc,
    int proto,
    union socket_address *sa);

MG_INTERNAL int mg_parse_address(const char *str, union socket_address *sa,
    int *proto, char *host, size_t host_len);
MG_INTERNAL void mg_call(struct mg_connection *nc,
    mg_event_handler_t ev_handler, void *user_data, int ev,
    void *ev_data);
void mg_forward(struct mg_connection *from, struct mg_connection *to);
MG_INTERNAL void mg_add_conn(struct mg_mgr *mgr, struct mg_connection *c);
MG_INTERNAL void mg_remove_conn(struct mg_connection *c);
MG_INTERNAL struct mg_connection *mg_create_connection(
    struct mg_mgr *mgr, mg_event_handler_t callback,
    struct mg_add_sock_opts opts);
#ifdef _WIN32
/* Retur value is the same as for MultiByteToWideChar. */
int to_wchar(const char *path, wchar_t *wbuf, size_t wbuf_len);
#endif

struct ctl_msg {
    mg_event_handler_t callback;
    char message[MG_CTL_MSG_MESSAGE_SIZE];
};

#if MG_ENABLE_MQTT
struct mg_mqtt_message;

#define MG_MQTT_ERROR_INCOMPLETE_MSG -1
#define MG_MQTT_ERROR_MALFORMED_MSG -2

MG_INTERNAL int parse_mqtt(struct mbuf *io, struct mg_mqtt_message *mm);
#endif

/* Forward declarations for testing. */
extern void *(*test_malloc)(size_t size);
extern void *(*test_calloc)(size_t count, size_t size);

#ifndef MIN
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#endif

#if MG_ENABLE_HTTP
struct mg_serve_http_opts;

MG_INTERNAL struct mg_http_proto_data *mg_http_create_proto_data(
    struct mg_connection *c);

/*
 * Reassemble the content of the buffer (buf, blen) which should be
 * in the HTTP chunked encoding, by collapsing data chunks to the
 * beginning of the buffer.
 *
 * If chunks get reassembled, modify hm->body to point to the reassembled
 * body and fire MG_EV_HTTP_CHUNK event. If handler sets MG_F_DELETE_CHUNK
 * in nc->flags, delete reassembled body from the mbuf.
 *
 * Return reassembled body size.
 */
MG_INTERNAL size_t mg_handle_chunked(struct mg_connection *nc,
    struct http_message *hm, char *buf,
    size_t blen);

#if MG_ENABLE_FILESYSTEM
MG_INTERNAL int mg_uri_to_local_path(struct http_message *hm,
    const struct mg_serve_http_opts *opts,
    char **local_path,
    struct mg_str *remainder);
MG_INTERNAL time_t mg_parse_date_string(const char *datetime);
MG_INTERNAL int mg_is_not_modified(struct http_message *hm, cs_stat_t *st);
#endif
#if MG_ENABLE_HTTP_CGI
MG_INTERNAL void mg_handle_cgi(struct mg_connection *nc, const char *prog,
    const struct mg_str *path_info,
    const struct http_message *hm,
    const struct mg_serve_http_opts *opts);
struct mg_http_proto_data_cgi;
MG_INTERNAL void mg_http_free_proto_data_cgi(struct mg_http_proto_data_cgi *d);
#endif
#if MG_ENABLE_HTTP_SSI
MG_INTERNAL void mg_handle_ssi_request(struct mg_connection *nc,
    struct http_message *hm,
    const char *path,
    const struct mg_serve_http_opts *opts);
#endif
#if MG_ENABLE_HTTP_WEBDAV
MG_INTERNAL int mg_is_dav_request(const struct mg_str *s);
MG_INTERNAL void mg_handle_propfind(struct mg_connection *nc, const char *path,
    cs_stat_t *stp, struct http_message *hm,
    struct mg_serve_http_opts *opts);
MG_INTERNAL void mg_handle_lock(struct mg_connection *nc, const char *path);
MG_INTERNAL void mg_handle_mkcol(struct mg_connection *nc, const char *path,
    struct http_message *hm);
MG_INTERNAL void mg_handle_move(struct mg_connection *c,
    const struct mg_serve_http_opts *opts,
    const char *path, struct http_message *hm);
MG_INTERNAL void mg_handle_delete(struct mg_connection *nc,
    const struct mg_serve_http_opts *opts,
    const char *path);
MG_INTERNAL void mg_handle_put(struct mg_connection *nc, const char *path,
    struct http_message *hm);
#endif
#if MG_ENABLE_HTTP_WEBSOCKET
MG_INTERNAL void mg_ws_handler(struct mg_connection *nc, int ev,
    void *ev_data MG_UD_ARG(void *user_data));
MG_INTERNAL void mg_ws_handshake(struct mg_connection *nc,
    const struct mg_str *key,
    struct http_message *);
#endif
#endif /* MG_ENABLE_HTTP */

MG_INTERNAL int mg_get_errno(void);

MG_INTERNAL void mg_close_conn(struct mg_connection *conn);

#if MG_ENABLE_SNTP
MG_INTERNAL int mg_sntp_parse_reply(const char *buf, int len,
    struct mg_sntp_message *msg);
#endif

#endif /* CS_MONGOOSE_SRC_INTERNAL_H_ */
#ifdef MG_MODULE_LINES
#line 1 "common/mg_mem.h"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CS_COMMON_MG_MEM_H_
#define CS_COMMON_MG_MEM_H_

#ifdef __cplusplus
extern "C" {
#endif

#ifndef MG_MALLOC
#define MG_MALLOC malloc
#endif

#ifndef MG_CALLOC
#define MG_CALLOC calloc
#endif

#ifndef MG_REALLOC
#define MG_REALLOC realloc
#endif

#ifndef MG_FREE
#define MG_FREE free
#endif

#ifdef __cplusplus
}
#endif

#endif /* CS_COMMON_MG_MEM_H_ */
#ifdef MG_MODULE_LINES
#line 1 "common/cs_base64.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef EXCLUDE_COMMON

 /* Amalgamated: #include "common/cs_base64.h" */

#include <string.h>

/* Amalgamated: #include "common/cs_dbg.h" */

/* ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/ */

#define NUM_UPPERCASES ('Z' - 'A' + 1)
#define NUM_LETTERS (NUM_UPPERCASES * 2)
#define NUM_DIGITS ('9' - '0' + 1)

/*
 * Emit a base64 code char.
 *
 * Doesn't use memory, thus it's safe to use to safely dump memory in crashdumps
 */
static void cs_base64_emit_code(struct cs_base64_ctx *ctx, int v) {
    if (v < NUM_UPPERCASES) {
        ctx->b64_putc(v + 'A', ctx->user_data);
    }
    else if (v < (NUM_LETTERS)) {
        ctx->b64_putc(v - NUM_UPPERCASES + 'a', ctx->user_data);
    }
    else if (v < (NUM_LETTERS + NUM_DIGITS)) {
        ctx->b64_putc(v - NUM_LETTERS + '0', ctx->user_data);
    }
    else {
        ctx->b64_putc(v - NUM_LETTERS - NUM_DIGITS == 0 ? '+' : '/',
            ctx->user_data);
    }
}

static void cs_base64_emit_chunk(struct cs_base64_ctx *ctx) {
    int a, b, c;

    a = ctx->chunk[0];
    b = ctx->chunk[1];
    c = ctx->chunk[2];

    cs_base64_emit_code(ctx, a >> 2);
    cs_base64_emit_code(ctx, ((a & 3) << 4) | (b >> 4));
    if (ctx->chunk_size > 1) {
        cs_base64_emit_code(ctx, (b & 15) << 2 | (c >> 6));
    }
    if (ctx->chunk_size > 2) {
        cs_base64_emit_code(ctx, c & 63);
    }
}

void cs_base64_init(struct cs_base64_ctx *ctx, cs_base64_putc_t b64_putc,
    void *user_data) {
    ctx->chunk_size = 0;
    ctx->b64_putc = b64_putc;
    ctx->user_data = user_data;
}

void cs_base64_update(struct cs_base64_ctx *ctx, const char *str, size_t len) {
    const unsigned char *src = (const unsigned char *)str;
    size_t i;
    for (i = 0; i < len; i++) {
        ctx->chunk[ctx->chunk_size++] = src[i];
        if (ctx->chunk_size == 3) {
            cs_base64_emit_chunk(ctx);
            ctx->chunk_size = 0;
        }
    }
}

void cs_base64_finish(struct cs_base64_ctx *ctx) {
    if (ctx->chunk_size > 0) {
        int i;
        memset(&ctx->chunk[ctx->chunk_size], 0, 3 - ctx->chunk_size);
        cs_base64_emit_chunk(ctx);
        for (i = 0; i < (3 - ctx->chunk_size); i++) {
            ctx->b64_putc('=', ctx->user_data);
        }
    }
}

#define BASE64_ENCODE_BODY                                                \
  static const char *b64 =                                                \
      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; \
  int i, j, a, b, c;                                                      \
                                                                          \
  for (i = j = 0; i < src_len; i += 3) {                                  \
    a = src[i];                                                           \
    b = i + 1 >= src_len ? 0 : src[i + 1];                                \
    c = i + 2 >= src_len ? 0 : src[i + 2];                                \
                                                                          \
    BASE64_OUT(b64[a >> 2]);                                              \
    BASE64_OUT(b64[((a & 3) << 4) | (b >> 4)]);                           \
    if (i + 1 < src_len) {                                                \
      BASE64_OUT(b64[(b & 15) << 2 | (c >> 6)]);                          \
    }                                                                     \
    if (i + 2 < src_len) {                                                \
      BASE64_OUT(b64[c & 63]);                                            \
    }                                                                     \
  }                                                                       \
                                                                          \
  while (j % 4 != 0) {                                                    \
    BASE64_OUT('=');                                                      \
  }                                                                       \
  BASE64_FLUSH()

#define BASE64_OUT(ch) \
  do {                 \
    dst[j++] = (ch);   \
  } while (0)

#define BASE64_FLUSH() \
  do {                 \
    dst[j++] = '\0';   \
  } while (0)

void cs_base64_encode(const unsigned char *src, int src_len, char *dst) {
    BASE64_ENCODE_BODY;
}

#undef BASE64_OUT
#undef BASE64_FLUSH

#if CS_ENABLE_STDIO
#define BASE64_OUT(ch)      \
  do {                      \
    fprintf(f, "%c", (ch)); \
    j++;                    \
  } while (0)

#define BASE64_FLUSH()

void cs_fprint_base64(FILE *f, const unsigned char *src, int src_len) {
    BASE64_ENCODE_BODY;
}

#undef BASE64_OUT
#undef BASE64_FLUSH
#endif /* CS_ENABLE_STDIO */

/* Convert one byte of encoded base64 input stream to 6-bit chunk */
static unsigned char from_b64(unsigned char ch) {
    /* Inverse lookup map */
    static const unsigned char tab[128] = {
        255, 255, 255, 255,
        255, 255, 255, 255, /*  0 */
        255, 255, 255, 255,
        255, 255, 255, 255, /*  8 */
        255, 255, 255, 255,
        255, 255, 255, 255, /*  16 */
        255, 255, 255, 255,
        255, 255, 255, 255, /*  24 */
        255, 255, 255, 255,
        255, 255, 255, 255, /*  32 */
        255, 255, 255, 62,
        255, 255, 255, 63, /*  40 */
        52,  53,  54,  55,
        56,  57,  58,  59, /*  48 */
        60,  61,  255, 255,
        255, 200, 255, 255, /*  56   '=' is 200, on index 61 */
        255, 0,   1,   2,
        3,   4,   5,   6, /*  64 */
        7,   8,   9,   10,
        11,  12,  13,  14, /*  72 */
        15,  16,  17,  18,
        19,  20,  21,  22, /*  80 */
        23,  24,  25,  255,
        255, 255, 255, 255, /*  88 */
        255, 26,  27,  28,
        29,  30,  31,  32, /*  96 */
        33,  34,  35,  36,
        37,  38,  39,  40, /*  104 */
        41,  42,  43,  44,
        45,  46,  47,  48, /*  112 */
        49,  50,  51,  255,
        255, 255, 255, 255, /*  120 */
    };
    return tab[ch & 127];
}

int cs_base64_decode(const unsigned char *s, int len, char *dst, int *dec_len) {
    unsigned char a, b, c, d;
    int orig_len = len;
    char *orig_dst = dst;
    while (len >= 4 && (a = from_b64(s[0])) != 255 &&
        (b = from_b64(s[1])) != 255 && (c = from_b64(s[2])) != 255 &&
        (d = from_b64(s[3])) != 255) {
        s += 4;
        len -= 4;
        if (a == 200 || b == 200) break; /* '=' can't be there */
        *dst++ = a << 2 | b >> 4;
        if (c == 200) break;
        *dst++ = b << 4 | c >> 2;
        if (d == 200) break;
        *dst++ = c << 6 | d;
    }
    *dst = 0;
    if (dec_len != NULL) *dec_len = (dst - orig_dst);
    return orig_len - len;
}

#endif /* EXCLUDE_COMMON */
#ifdef MG_MODULE_LINES
#line 1 "common/cs_dbg.h"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CS_COMMON_CS_DBG_H_
#define CS_COMMON_CS_DBG_H_

 /* Amalgamated: #include "common/platform.h" */

#if CS_ENABLE_STDIO
#include <stdio.h>
#endif

#ifndef CS_ENABLE_DEBUG
#define CS_ENABLE_DEBUG 0
#endif

#ifndef CS_LOG_PREFIX_LEN
#define CS_LOG_PREFIX_LEN 24
#endif

#ifndef CS_LOG_ENABLE_TS_DIFF
#define CS_LOG_ENABLE_TS_DIFF 0
#endif

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

    /*
     * Log level; `LL_INFO` is the default. Use `cs_log_set_level()` to change it.
     */
    enum cs_log_level {
        LL_NONE = -1,
        LL_ERROR = 0,
        LL_WARN = 1,
        LL_INFO = 2,
        LL_DEBUG = 3,
        LL_VERBOSE_DEBUG = 4,

        _LL_MIN = -2,
        _LL_MAX = 5,
    };

    /*
     * Set max log level to print; messages with the level above the given one will
     * not be printed.
     */
    void cs_log_set_level(enum cs_log_level level);

    /*
     * A comma-separated set of prefix=level.
     * prefix is matched against the log prefix exactly as printed, including line
     * number, but partial match is ok. Check stops on first matching entry.
     * If nothing matches, default level is used.
     *
     * Examples:
     *   main.c:=4 - everything from main C at verbose debug level.
     *   mongoose.c=1,mjs.c=1,=4 - everything at verbose debug except mg_* and mjs_*
     *
     */
    void cs_log_set_file_level(const char *file_level);

    /*
     * Helper function which prints message prefix with the given `level`.
     * If message should be printed (according to the current log level
     * and filter), prints the prefix and returns 1, otherwise returns 0.
     *
     * Clients should typically just use `LOG()` macro.
     */
    int cs_log_print_prefix(enum cs_log_level level, const char *fname, int line);

    extern enum cs_log_level cs_log_level;

#if CS_ENABLE_STDIO

    /*
     * Set file to write logs into. If `NULL`, logs go to `stderr`.
     */
    void cs_log_set_file(FILE *file);

    /*
     * Prints log to the current log file, appends "\n" in the end and flushes the
     * stream.
     */
    void cs_log_printf(const char *fmt, ...) PRINTF_LIKE(1, 2);

#if CS_ENABLE_STDIO

    /*
     * Format and print message `x` with the given level `l`. Example:
     *
     * ```c
     * LOG(LL_INFO, ("my info message: %d", 123));
     * LOG(LL_DEBUG, ("my debug message: %d", 123));
     * ```
     */
#define LOG(l, x)                                     \
  do {                                                \
    if (cs_log_print_prefix(l, __FILE__, __LINE__)) { \
      cs_log_printf x;                                \
    }                                                 \
  } while (0)

#else

#define LOG(l, x) ((void) l)

#endif

#ifndef CS_NDEBUG

    /*
     * Shortcut for `LOG(LL_VERBOSE_DEBUG, (...))`
     */
#define DBG(x) LOG(LL_VERBOSE_DEBUG, x)

#else /* NDEBUG */

#define DBG(x)

#endif

#else /* CS_ENABLE_STDIO */

#define LOG(l, x)
#define DBG(x)

#endif

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* CS_COMMON_CS_DBG_H_ */
#ifdef MG_MODULE_LINES
#line 1 "common/cs_dbg.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

 /* Amalgamated: #include "common/cs_dbg.h" */

#include <stdarg.h>
#include <stdio.h>
#include <string.h>

/* Amalgamated: #include "common/cs_time.h" */
/* Amalgamated: #include "common/str_util.h" */

enum cs_log_level cs_log_level WEAK =
#if CS_ENABLE_DEBUG
    LL_VERBOSE_DEBUG;
#else
    LL_ERROR;
#endif

#if CS_ENABLE_STDIO
static char *s_file_level = NULL;

void cs_log_set_file_level(const char *file_level) WEAK;

FILE *cs_log_file WEAK = NULL;

#if CS_LOG_ENABLE_TS_DIFF
double cs_log_ts WEAK;
#endif

enum cs_log_level cs_log_cur_msg_level WEAK = LL_NONE;

void cs_log_set_file_level(const char *file_level) {
    char *fl = s_file_level;
    if (file_level != NULL) {
        s_file_level = strdup(file_level);
    }
    else {
        s_file_level = NULL;
    }
    free(fl);
}

int cs_log_print_prefix(enum cs_log_level level, const char *file, int ln) WEAK;
int cs_log_print_prefix(enum cs_log_level level, const char *file, int ln) {
    char prefix[CS_LOG_PREFIX_LEN], *q;
    const char *p;
    size_t fl = 0, ll = 0, pl = 0;

    if (level > cs_log_level && s_file_level == NULL) return 0;

    p = file + strlen(file);

    while (p != file) {
        const char c = *(p - 1);
        if (c == '/' || c == '\\') break;
        p--;
        fl++;
    }

    ll = (ln < 10000 ? (ln < 1000 ? (ln < 100 ? (ln < 10 ? 1 : 2) : 3) : 4) : 5);
    if (fl > (sizeof(prefix) - ll - 2)) fl = (sizeof(prefix) - ll - 2);

    pl = fl + 1 + ll;
    memcpy(prefix, p, fl);
    q = prefix + pl;
    memset(q, ' ', sizeof(prefix) - pl);
    do {
        *(--q) = '0' + (ln % 10);
        ln /= 10;
    } while (ln > 0);
    *(--q) = ':';

    if (s_file_level != NULL) {
        enum cs_log_level pll = cs_log_level;
        struct mg_str fl = mg_mk_str(s_file_level), ps = MG_MK_STR_N(prefix, pl);
        struct mg_str k, v;
        while ((fl = mg_next_comma_list_entry_n(fl, &k, &v)).p != NULL) {
            bool yes = !(!mg_str_starts_with(ps, k) || v.len == 0);
            if (!yes) continue;
            pll = (enum cs_log_level)(*v.p - '0');
            break;
        }
        if (level > pll) return 0;
    }

    if (cs_log_file == NULL) cs_log_file = stderr;
    cs_log_cur_msg_level = level;
    fwrite(prefix, 1, sizeof(prefix), cs_log_file);
#if CS_LOG_ENABLE_TS_DIFF
    {
        double now = cs_time();
        fprintf(cs_log_file, "%7u ", (unsigned int)((now - cs_log_ts) * 1000000));
        cs_log_ts = now;
    }
#endif
    return 1;
}

void cs_log_printf(const char *fmt, ...) WEAK;
void cs_log_printf(const char *fmt, ...) {
    va_list ap;
    va_start(ap, fmt);
    vfprintf(cs_log_file, fmt, ap);
    va_end(ap);
    fputc('\n', cs_log_file);
    fflush(cs_log_file);
    cs_log_cur_msg_level = LL_NONE;
}

void cs_log_set_file(FILE *file) WEAK;
void cs_log_set_file(FILE *file) {
    cs_log_file = file;
}

#else

void cs_log_set_file_level(const char *file_level) {
    (void)file_level;
}

#endif /* CS_ENABLE_STDIO */

void cs_log_set_level(enum cs_log_level level) WEAK;
void cs_log_set_level(enum cs_log_level level) {
    cs_log_level = level;
#if CS_LOG_ENABLE_TS_DIFF && CS_ENABLE_STDIO
    cs_log_ts = cs_time();
#endif
}
#ifdef MG_MODULE_LINES
#line 1 "common/cs_dirent.h"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CS_COMMON_CS_DIRENT_H_
#define CS_COMMON_CS_DIRENT_H_

#include <limits.h>

 /* Amalgamated: #include "common/platform.h" */

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#ifdef CS_DEFINE_DIRENT
    typedef struct { int dummy; } DIR;

    struct dirent {
        int d_ino;
#ifdef _WIN32
        char d_name[MAX_PATH];
#else
        /* TODO(rojer): Use PATH_MAX but make sure it's sane on every platform */
        char d_name[256];
#endif
    };

    DIR *opendir(const char *dir_name);
    int closedir(DIR *dir);
    struct dirent *readdir(DIR *dir);
#endif /* CS_DEFINE_DIRENT */

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* CS_COMMON_CS_DIRENT_H_ */
#ifdef MG_MODULE_LINES
#line 1 "common/cs_dirent.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef EXCLUDE_COMMON

 /* Amalgamated: #include "common/mg_mem.h" */
 /* Amalgamated: #include "common/cs_dirent.h" */

 /*
  * This file contains POSIX opendir/closedir/readdir API implementation
  * for systems which do not natively support it (e.g. Windows).
  */

#ifdef _WIN32
struct win32_dir {
    DIR d;
    HANDLE handle;
    WIN32_FIND_DATAW info;
    struct dirent result;
};

DIR *opendir(const char *name) {
    struct win32_dir *dir = NULL;
    wchar_t wpath[MAX_PATH];
    DWORD attrs;

    if (name == NULL) {
        SetLastError(ERROR_BAD_ARGUMENTS);
    }
    else if ((dir = (struct win32_dir *) MG_MALLOC(sizeof(*dir))) == NULL) {
        SetLastError(ERROR_NOT_ENOUGH_MEMORY);
    }
    else {
        to_wchar(name, wpath, ARRAY_SIZE(wpath));
        attrs = GetFileAttributesW(wpath);
        if (attrs != 0xFFFFFFFF && (attrs & FILE_ATTRIBUTE_DIRECTORY)) {
            (void)wcscat(wpath, L"\\*");
            dir->handle = FindFirstFileW(wpath, &dir->info);
            dir->result.d_name[0] = '\0';
        }
        else {
            MG_FREE(dir);
            dir = NULL;
        }
    }

    return (DIR *)dir;
}

int closedir(DIR *d) {
    struct win32_dir *dir = (struct win32_dir *) d;
    int result = 0;

    if (dir != NULL) {
        if (dir->handle != INVALID_HANDLE_VALUE)
            result = FindClose(dir->handle) ? 0 : -1;
        MG_FREE(dir);
    }
    else {
        result = -1;
        SetLastError(ERROR_BAD_ARGUMENTS);
    }

    return result;
}

struct dirent *readdir(DIR *d) {
    struct win32_dir *dir = (struct win32_dir *) d;
    struct dirent *result = NULL;

    if (dir) {
        memset(&dir->result, 0, sizeof(dir->result));
        if (dir->handle != INVALID_HANDLE_VALUE) {
            result = &dir->result;
            (void)WideCharToMultiByte(CP_UTF8, 0, dir->info.cFileName, -1,
                result->d_name, sizeof(result->d_name), NULL,
                NULL);

            if (!FindNextFileW(dir->handle, &dir->info)) {
                (void)FindClose(dir->handle);
                dir->handle = INVALID_HANDLE_VALUE;
            }

        }
        else {
            SetLastError(ERROR_FILE_NOT_FOUND);
        }
    }
    else {
        SetLastError(ERROR_BAD_ARGUMENTS);
    }

    return result;
}
#endif

#endif /* EXCLUDE_COMMON */

/* ISO C requires a translation unit to contain at least one declaration */
typedef int cs_dirent_dummy;
#ifdef MG_MODULE_LINES
#line 1 "common/cs_time.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

 /* Amalgamated: #include "common/cs_time.h" */

#ifndef _WIN32
#include <stddef.h>
/*
 * There is no sys/time.h on ARMCC.
 */
#if !(defined(__ARMCC_VERSION) || defined(__ICCARM__)) && \
    !defined(__TI_COMPILER_VERSION__) &&                  \
    (!defined(CS_PLATFORM) || CS_PLATFORM != CS_P_NXP_LPC)
#include <sys/time.h>
#endif
#else
#include <windows.h>
#endif

double cs_time(void) WEAK;
double cs_time(void) {
    double now;
#ifndef _WIN32
    struct timeval tv;
    if (gettimeofday(&tv, NULL /* tz */) != 0) return 0;
    now = (double)tv.tv_sec + (((double)tv.tv_usec) / 1000000.0);
#else
    SYSTEMTIME sysnow;
    FILETIME ftime;
    GetLocalTime(&sysnow);
    SystemTimeToFileTime(&sysnow, &ftime);
    /*
     * 1. VC 6.0 doesn't support conversion uint64 -> double, so, using int64
     * This should not cause a problems in this (21th) century
     * 2. Windows FILETIME is a number of 100-nanosecond intervals since January
     * 1, 1601 while time_t is a number of _seconds_ since January 1, 1970 UTC,
     * thus, we need to convert to seconds and adjust amount (subtract 11644473600
     * seconds)
     */
    now = (double)(((int64_t)ftime.dwLowDateTime +
        ((int64_t)ftime.dwHighDateTime << 32)) /
        10000000.0) -
        11644473600;
#endif /* _WIN32 */
    return now;
}

double cs_timegm(const struct tm *tm) {
    /* Month-to-day offset for non-leap-years. */
    static const int month_day[12] = { 0,   31,  59,  90,  120, 151,
                                      181, 212, 243, 273, 304, 334 };

    /* Most of the calculation is easy; leap years are the main difficulty. */
    int month = tm->tm_mon % 12;
    int year = tm->tm_year + tm->tm_mon / 12;
    int year_for_leap;
    int64_t rt;

    if (month < 0) { /* Negative values % 12 are still negative. */
        month += 12;
        --year;
    }

    /* This is the number of Februaries since 1900. */
    year_for_leap = (month > 1) ? year + 1 : year;

    rt =
        tm->tm_sec /* Seconds */
        +
        60 *
        (tm->tm_min /* Minute = 60 seconds */
            +
            60 * (tm->tm_hour /* Hour = 60 minutes */
                +
                24 * (month_day[month] + tm->tm_mday - 1 /* Day = 24 hours */
                    + 365 * (year - 70)                /* Year = 365 days */
                    + (year_for_leap - 69) / 4 /* Every 4 years is leap... */
                    - (year_for_leap - 1) / 100 /* Except centuries... */
                    + (year_for_leap + 299) / 400))); /* Except 400s. */
    return rt < 0 ? -1 : (double)rt;
}
#ifdef MG_MODULE_LINES
#line 1 "common/cs_endian.h"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CS_COMMON_CS_ENDIAN_H_
#define CS_COMMON_CS_ENDIAN_H_

#ifdef __cplusplus
extern "C" {
#endif

    /*
     * clang with std=-c99 uses __LITTLE_ENDIAN, by default
     * while for ex, RTOS gcc - LITTLE_ENDIAN, by default
     * it depends on __USE_BSD, but let's have everything
     */
#if !defined(BYTE_ORDER) && defined(__BYTE_ORDER)
#define BYTE_ORDER __BYTE_ORDER
#ifndef LITTLE_ENDIAN
#define LITTLE_ENDIAN __LITTLE_ENDIAN
#endif /* LITTLE_ENDIAN */
#ifndef BIG_ENDIAN
#define BIG_ENDIAN __LITTLE_ENDIAN
#endif /* BIG_ENDIAN */
#endif /* BYTE_ORDER */

#ifdef __cplusplus
}
#endif

#endif /* CS_COMMON_CS_ENDIAN_H_ */
#ifdef MG_MODULE_LINES
#line 1 "common/cs_md5.c"
#endif
/*
 * This code implements the MD5 message-digest algorithm.
 * The algorithm is due to Ron Rivest.  This code was
 * written by Colin Plumb in 1993, no copyright is claimed.
 * This code is in the public domain; do with it what you wish.
 *
 * Equivalent code is available from RSA Data Security, Inc.
 * This code has been tested against that, and is equivalent,
 * except that you don't need to include two pages of legalese
 * with every copy.
 *
 * To compute the message digest of a chunk of bytes, declare an
 * MD5Context structure, pass it to MD5Init, call MD5Update as
 * needed on buffers full of bytes, and then call MD5Final, which
 * will fill a supplied 16-byte array with the digest.
 */

 /* Amalgamated: #include "common/cs_md5.h" */
 /* Amalgamated: #include "common/str_util.h" */

#if !defined(EXCLUDE_COMMON)
#if !CS_DISABLE_MD5

/* Amalgamated: #include "common/cs_endian.h" */

static void byteReverse(unsigned char *buf, unsigned longs) {
    /* Forrest: MD5 expect LITTLE_ENDIAN, swap if BIG_ENDIAN */
#if BYTE_ORDER == BIG_ENDIAN
    do {
        uint32_t t = (uint32_t)((unsigned)buf[3] << 8 | buf[2]) << 16 |
            ((unsigned)buf[1] << 8 | buf[0]);
        *(uint32_t *)buf = t;
        buf += 4;
    } while (--longs);
#else
    (void)buf;
    (void)longs;
#endif
}

#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))

#define MD5STEP(f, w, x, y, z, data, s) \
  (w += f(x, y, z) + data, w = w << s | w >> (32 - s), w += x)

/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
void cs_md5_init(cs_md5_ctx *ctx) {
    ctx->buf[0] = 0x67452301;
    ctx->buf[1] = 0xefcdab89;
    ctx->buf[2] = 0x98badcfe;
    ctx->buf[3] = 0x10325476;

    ctx->bits[0] = 0;
    ctx->bits[1] = 0;
}

static void cs_md5_transform(uint32_t buf[4], uint32_t const in[16]) {
    register uint32_t a, b, c, d;

    a = buf[0];
    b = buf[1];
    c = buf[2];
    d = buf[3];

    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);

    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);

    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);

    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);

    buf[0] += a;
    buf[1] += b;
    buf[2] += c;
    buf[3] += d;
}

void cs_md5_update(cs_md5_ctx *ctx, const unsigned char *buf, size_t len) {
    uint32_t t;

    t = ctx->bits[0];
    if ((ctx->bits[0] = t + ((uint32_t)len << 3)) < t) ctx->bits[1]++;
    ctx->bits[1] += (uint32_t)len >> 29;

    t = (t >> 3) & 0x3f;

    if (t) {
        unsigned char *p = (unsigned char *)ctx->in + t;

        t = 64 - t;
        if (len < t) {
            memcpy(p, buf, len);
            return;
        }
        memcpy(p, buf, t);
        byteReverse(ctx->in, 16);
        cs_md5_transform(ctx->buf, (uint32_t *)ctx->in);
        buf += t;
        len -= t;
    }

    while (len >= 64) {
        memcpy(ctx->in, buf, 64);
        byteReverse(ctx->in, 16);
        cs_md5_transform(ctx->buf, (uint32_t *)ctx->in);
        buf += 64;
        len -= 64;
    }

    memcpy(ctx->in, buf, len);
}

void cs_md5_final(unsigned char digest[16], cs_md5_ctx *ctx) {
    unsigned count;
    unsigned char *p;
    uint32_t *a;

    count = (ctx->bits[0] >> 3) & 0x3F;

    p = ctx->in + count;
    *p++ = 0x80;
    count = 64 - 1 - count;
    if (count < 8) {
        memset(p, 0, count);
        byteReverse(ctx->in, 16);
        cs_md5_transform(ctx->buf, (uint32_t *)ctx->in);
        memset(ctx->in, 0, 56);
    }
    else {
        memset(p, 0, count - 8);
    }
    byteReverse(ctx->in, 14);

    a = (uint32_t *)ctx->in;
    a[14] = ctx->bits[0];
    a[15] = ctx->bits[1];

    cs_md5_transform(ctx->buf, (uint32_t *)ctx->in);
    byteReverse((unsigned char *)ctx->buf, 4);
    memcpy(digest, ctx->buf, 16);
    memset((char *)ctx, 0, sizeof(*ctx));
}

#endif /* CS_DISABLE_MD5 */
#endif /* EXCLUDE_COMMON */
#ifdef MG_MODULE_LINES
#line 1 "common/cs_sha1.c"
#endif
/* Copyright(c) By Steve Reid <steve@edmweb.com> */
/* 100% Public Domain */

/* Amalgamated: #include "common/cs_sha1.h" */

#if !CS_DISABLE_SHA1 && !defined(EXCLUDE_COMMON)

/* Amalgamated: #include "common/cs_endian.h" */

#define SHA1HANDSOFF
#if defined(__sun)
/* Amalgamated: #include "common/solarisfixes.h" */
#endif

union char64long16 {
    unsigned char c[64];
    uint32_t l[16];
};

#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))

static uint32_t blk0(union char64long16 *block, int i) {
    /* Forrest: SHA expect BIG_ENDIAN, swap if LITTLE_ENDIAN */
#if BYTE_ORDER == LITTLE_ENDIAN
    block->l[i] =
        (rol(block->l[i], 24) & 0xFF00FF00) | (rol(block->l[i], 8) & 0x00FF00FF);
#endif
    return block->l[i];
}

/* Avoid redefine warning (ARM /usr/include/sys/ucontext.h define R0~R4) */
#undef blk
#undef R0
#undef R1
#undef R2
#undef R3
#undef R4

#define blk(i)                                                               \
  (block->l[i & 15] = rol(block->l[(i + 13) & 15] ^ block->l[(i + 8) & 15] ^ \
                              block->l[(i + 2) & 15] ^ block->l[i & 15],     \
                          1))
#define R0(v, w, x, y, z, i)                                          \
  z += ((w & (x ^ y)) ^ y) + blk0(block, i) + 0x5A827999 + rol(v, 5); \
  w = rol(w, 30);
#define R1(v, w, x, y, z, i)                                  \
  z += ((w & (x ^ y)) ^ y) + blk(i) + 0x5A827999 + rol(v, 5); \
  w = rol(w, 30);
#define R2(v, w, x, y, z, i)                          \
  z += (w ^ x ^ y) + blk(i) + 0x6ED9EBA1 + rol(v, 5); \
  w = rol(w, 30);
#define R3(v, w, x, y, z, i)                                        \
  z += (((w | x) & y) | (w & x)) + blk(i) + 0x8F1BBCDC + rol(v, 5); \
  w = rol(w, 30);
#define R4(v, w, x, y, z, i)                          \
  z += (w ^ x ^ y) + blk(i) + 0xCA62C1D6 + rol(v, 5); \
  w = rol(w, 30);

void cs_sha1_transform(uint32_t state[5], const unsigned char buffer[64]) {
    uint32_t a, b, c, d, e;
    union char64long16 block[1];

    memcpy(block, buffer, 64);
    a = state[0];
    b = state[1];
    c = state[2];
    d = state[3];
    e = state[4];
    R0(a, b, c, d, e, 0);
    R0(e, a, b, c, d, 1);
    R0(d, e, a, b, c, 2);
    R0(c, d, e, a, b, 3);
    R0(b, c, d, e, a, 4);
    R0(a, b, c, d, e, 5);
    R0(e, a, b, c, d, 6);
    R0(d, e, a, b, c, 7);
    R0(c, d, e, a, b, 8);
    R0(b, c, d, e, a, 9);
    R0(a, b, c, d, e, 10);
    R0(e, a, b, c, d, 11);
    R0(d, e, a, b, c, 12);
    R0(c, d, e, a, b, 13);
    R0(b, c, d, e, a, 14);
    R0(a, b, c, d, e, 15);
    R1(e, a, b, c, d, 16);
    R1(d, e, a, b, c, 17);
    R1(c, d, e, a, b, 18);
    R1(b, c, d, e, a, 19);
    R2(a, b, c, d, e, 20);
    R2(e, a, b, c, d, 21);
    R2(d, e, a, b, c, 22);
    R2(c, d, e, a, b, 23);
    R2(b, c, d, e, a, 24);
    R2(a, b, c, d, e, 25);
    R2(e, a, b, c, d, 26);
    R2(d, e, a, b, c, 27);
    R2(c, d, e, a, b, 28);
    R2(b, c, d, e, a, 29);
    R2(a, b, c, d, e, 30);
    R2(e, a, b, c, d, 31);
    R2(d, e, a, b, c, 32);
    R2(c, d, e, a, b, 33);
    R2(b, c, d, e, a, 34);
    R2(a, b, c, d, e, 35);
    R2(e, a, b, c, d, 36);
    R2(d, e, a, b, c, 37);
    R2(c, d, e, a, b, 38);
    R2(b, c, d, e, a, 39);
    R3(a, b, c, d, e, 40);
    R3(e, a, b, c, d, 41);
    R3(d, e, a, b, c, 42);
    R3(c, d, e, a, b, 43);
    R3(b, c, d, e, a, 44);
    R3(a, b, c, d, e, 45);
    R3(e, a, b, c, d, 46);
    R3(d, e, a, b, c, 47);
    R3(c, d, e, a, b, 48);
    R3(b, c, d, e, a, 49);
    R3(a, b, c, d, e, 50);
    R3(e, a, b, c, d, 51);
    R3(d, e, a, b, c, 52);
    R3(c, d, e, a, b, 53);
    R3(b, c, d, e, a, 54);
    R3(a, b, c, d, e, 55);
    R3(e, a, b, c, d, 56);
    R3(d, e, a, b, c, 57);
    R3(c, d, e, a, b, 58);
    R3(b, c, d, e, a, 59);
    R4(a, b, c, d, e, 60);
    R4(e, a, b, c, d, 61);
    R4(d, e, a, b, c, 62);
    R4(c, d, e, a, b, 63);
    R4(b, c, d, e, a, 64);
    R4(a, b, c, d, e, 65);
    R4(e, a, b, c, d, 66);
    R4(d, e, a, b, c, 67);
    R4(c, d, e, a, b, 68);
    R4(b, c, d, e, a, 69);
    R4(a, b, c, d, e, 70);
    R4(e, a, b, c, d, 71);
    R4(d, e, a, b, c, 72);
    R4(c, d, e, a, b, 73);
    R4(b, c, d, e, a, 74);
    R4(a, b, c, d, e, 75);
    R4(e, a, b, c, d, 76);
    R4(d, e, a, b, c, 77);
    R4(c, d, e, a, b, 78);
    R4(b, c, d, e, a, 79);
    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    state[4] += e;
    /* Erase working structures. The order of operations is important,
     * used to ensure that compiler doesn't optimize those out. */
    memset(block, 0, sizeof(block));
    a = b = c = d = e = 0;
    (void)a;
    (void)b;
    (void)c;
    (void)d;
    (void)e;
}

void cs_sha1_init(cs_sha1_ctx *context) {
    context->state[0] = 0x67452301;
    context->state[1] = 0xEFCDAB89;
    context->state[2] = 0x98BADCFE;
    context->state[3] = 0x10325476;
    context->state[4] = 0xC3D2E1F0;
    context->count[0] = context->count[1] = 0;
}

void cs_sha1_update(cs_sha1_ctx *context, const unsigned char *data,
    uint32_t len) {
    uint32_t i, j;

    j = context->count[0];
    if ((context->count[0] += len << 3) < j) context->count[1]++;
    context->count[1] += (len >> 29);
    j = (j >> 3) & 63;
    if ((j + len) > 63) {
        memcpy(&context->buffer[j], data, (i = 64 - j));
        cs_sha1_transform(context->state, context->buffer);
        for (; i + 63 < len; i += 64) {
            cs_sha1_transform(context->state, &data[i]);
        }
        j = 0;
    }
    else
        i = 0;
    memcpy(&context->buffer[j], &data[i], len - i);
}

void cs_sha1_final(unsigned char digest[20], cs_sha1_ctx *context) {
    unsigned i;
    unsigned char finalcount[8], c;

    for (i = 0; i < 8; i++) {
        finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)] >>
            ((3 - (i & 3)) * 8)) &
            255);
    }
    c = 0200;
    cs_sha1_update(context, &c, 1);
    while ((context->count[0] & 504) != 448) {
        c = 0000;
        cs_sha1_update(context, &c, 1);
    }
    cs_sha1_update(context, finalcount, 8);
    for (i = 0; i < 20; i++) {
        digest[i] =
            (unsigned char)((context->state[i >> 2] >> ((3 - (i & 3)) * 8)) & 255);
    }
    memset(context, '\0', sizeof(*context));
    memset(&finalcount, '\0', sizeof(finalcount));
}

void cs_hmac_sha1(const unsigned char *key, size_t keylen,
    const unsigned char *data, size_t datalen,
    unsigned char out[20]) {
    cs_sha1_ctx ctx;
    unsigned char buf1[64], buf2[64], tmp_key[20], i;

    if (keylen > sizeof(buf1)) {
        cs_sha1_init(&ctx);
        cs_sha1_update(&ctx, key, keylen);
        cs_sha1_final(tmp_key, &ctx);
        key = tmp_key;
        keylen = sizeof(tmp_key);
    }

    memset(buf1, 0, sizeof(buf1));
    memset(buf2, 0, sizeof(buf2));
    memcpy(buf1, key, keylen);
    memcpy(buf2, key, keylen);

    for (i = 0; i < sizeof(buf1); i++) {
        buf1[i] ^= 0x36;
        buf2[i] ^= 0x5c;
    }

    cs_sha1_init(&ctx);
    cs_sha1_update(&ctx, buf1, sizeof(buf1));
    cs_sha1_update(&ctx, data, datalen);
    cs_sha1_final(out, &ctx);

    cs_sha1_init(&ctx);
    cs_sha1_update(&ctx, buf2, sizeof(buf2));
    cs_sha1_update(&ctx, out, 20);
    cs_sha1_final(out, &ctx);
}

#endif /* EXCLUDE_COMMON */
#ifdef MG_MODULE_LINES
#line 1 "common/mbuf.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef EXCLUDE_COMMON

#include <assert.h>
#include <string.h>
 /* Amalgamated: #include "common/mbuf.h" */

#ifndef MBUF_REALLOC
#define MBUF_REALLOC realloc
#endif

#ifndef MBUF_FREE
#define MBUF_FREE free
#endif

void mbuf_init(struct mbuf *mbuf, size_t initial_size) WEAK;
void mbuf_init(struct mbuf *mbuf, size_t initial_size) {
    mbuf->len = mbuf->size = 0;
    mbuf->buf = NULL;
    mbuf_resize(mbuf, initial_size);
}

void mbuf_free(struct mbuf *mbuf) WEAK;
void mbuf_free(struct mbuf *mbuf) {
    if (mbuf->buf != NULL) {
        MBUF_FREE(mbuf->buf);
        mbuf_init(mbuf, 0);
    }
}

void mbuf_resize(struct mbuf *a, size_t new_size) WEAK;
void mbuf_resize(struct mbuf *a, size_t new_size) {
    if (new_size > a->size || (new_size < a->size && new_size >= a->len)) {
        char *buf = (char *)MBUF_REALLOC(a->buf, new_size);
        /*
         * In case realloc fails, there's not much we can do, except keep things as
         * they are. Note that NULL is a valid return value from realloc when
         * size == 0, but that is covered too.
         */
        if (buf == NULL && new_size != 0) return;
        a->buf = buf;
        a->size = new_size;
    }
}

void mbuf_trim(struct mbuf *mbuf) WEAK;
void mbuf_trim(struct mbuf *mbuf) {
    mbuf_resize(mbuf, mbuf->len);
}

size_t mbuf_insert(struct mbuf *a, size_t off, const void *buf, size_t) WEAK;
size_t mbuf_insert(struct mbuf *a, size_t off, const void *buf, size_t len) {
    char *p = NULL;

    assert(a != NULL);
    assert(a->len <= a->size);
    assert(off <= a->len);

    /* check overflow */
    if (~(size_t)0 - (size_t)a->buf < len) return 0;

    if (a->len + len <= a->size) {
        memmove(a->buf + off + len, a->buf + off, a->len - off);
        if (buf != NULL) {
            memcpy(a->buf + off, buf, len);
        }
        a->len += len;
    }
    else {
        size_t min_size = (a->len + len);
        size_t new_size = (size_t)(min_size * MBUF_SIZE_MULTIPLIER);
        if (new_size - min_size > MBUF_SIZE_MAX_HEADROOM) {
            new_size = min_size + MBUF_SIZE_MAX_HEADROOM;
        }
        p = (char *)MBUF_REALLOC(a->buf, new_size);
        if (p == NULL && new_size != min_size) {
            new_size = min_size;
            p = (char *)MBUF_REALLOC(a->buf, new_size);
        }
        if (p != NULL) {
            a->buf = p;
            if (off != a->len) {
                memmove(a->buf + off + len, a->buf + off, a->len - off);
            }
            if (buf != NULL) memcpy(a->buf + off, buf, len);
            a->len += len;
            a->size = new_size;
        }
        else {
            len = 0;
        }
    }

    return len;
}

size_t mbuf_append(struct mbuf *a, const void *buf, size_t len) WEAK;
size_t mbuf_append(struct mbuf *a, const void *buf, size_t len) {
    return mbuf_insert(a, a->len, buf, len);
}

size_t mbuf_append_and_free(struct mbuf *a, void *buf, size_t len) WEAK;
size_t mbuf_append_and_free(struct mbuf *a, void *data, size_t len) {
    size_t ret;
    /* Optimization: if the buffer is currently empty,
     * take over the user-provided buffer. */
    if (a->len == 0) {
        if (a->buf != NULL) free(a->buf);
        a->buf = (char *)data;
        a->len = a->size = len;
        return len;
    }
    ret = mbuf_insert(a, a->len, data, len);
    free(data);
    return ret;
}

void mbuf_remove(struct mbuf *mb, size_t n) WEAK;
void mbuf_remove(struct mbuf *mb, size_t n) {
    if (n > 0 && n <= mb->len) {
        memmove(mb->buf, mb->buf + n, mb->len - n);
        mb->len -= n;
    }
}

void mbuf_clear(struct mbuf *mb) WEAK;
void mbuf_clear(struct mbuf *mb) {
    mb->len = 0;
}

void mbuf_move(struct mbuf *from, struct mbuf *to) WEAK;
void mbuf_move(struct mbuf *from, struct mbuf *to) {
    memcpy(to, from, sizeof(*to));
    memset(from, 0, sizeof(*from));
}

#endif /* EXCLUDE_COMMON */
#ifdef MG_MODULE_LINES
#line 1 "common/mg_str.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

 /* Amalgamated: #include "common/mg_mem.h" */
 /* Amalgamated: #include "common/mg_str.h" */
 /* Amalgamated: #include "common/platform.h" */

#include <ctype.h>
#include <stdlib.h>
#include <string.h>

int mg_ncasecmp(const char *s1, const char *s2, size_t len) WEAK;

struct mg_str mg_mk_str(const char *s) WEAK;
struct mg_str mg_mk_str(const char *s) {
    struct mg_str ret = { s, 0 };
    if (s != NULL) ret.len = strlen(s);
    return ret;
}

struct mg_str mg_mk_str_n(const char *s, size_t len) WEAK;
struct mg_str mg_mk_str_n(const char *s, size_t len) {
    struct mg_str ret = { s, len };
    return ret;
}

int mg_vcmp(const struct mg_str *str1, const char *str2) WEAK;
int mg_vcmp(const struct mg_str *str1, const char *str2) {
    size_t n2 = strlen(str2), n1 = str1->len;
    int r = strncmp(str1->p, str2, (n1 < n2) ? n1 : n2);
    if (r == 0) {
        return n1 - n2;
    }
    return r;
}

int mg_vcasecmp(const struct mg_str *str1, const char *str2) WEAK;
int mg_vcasecmp(const struct mg_str *str1, const char *str2) {
    size_t n2 = strlen(str2), n1 = str1->len;
    int r = mg_ncasecmp(str1->p, str2, (n1 < n2) ? n1 : n2);
    if (r == 0) {
        return n1 - n2;
    }
    return r;
}

static struct mg_str mg_strdup_common(const struct mg_str s,
    int nul_terminate) {
    struct mg_str r = { NULL, 0 };
    if (s.len > 0 && s.p != NULL) {
        char *sc = (char *)MG_MALLOC(s.len + (nul_terminate ? 1 : 0));
        if (sc != NULL) {
            memcpy(sc, s.p, s.len);
            if (nul_terminate) sc[s.len] = '\0';
            r.p = sc;
            r.len = s.len;
        }
    }
    return r;
}

struct mg_str mg_strdup(const struct mg_str s) WEAK;
struct mg_str mg_strdup(const struct mg_str s) {
    return mg_strdup_common(s, 0 /* NUL-terminate */);
}

struct mg_str mg_strdup_nul(const struct mg_str s) WEAK;
struct mg_str mg_strdup_nul(const struct mg_str s) {
    return mg_strdup_common(s, 1 /* NUL-terminate */);
}

const char *mg_strchr(const struct mg_str s, int c) WEAK;
const char *mg_strchr(const struct mg_str s, int c) {
    size_t i;
    for (i = 0; i < s.len; i++) {
        if (s.p[i] == c) return &s.p[i];
    }
    return NULL;
}

int mg_strcmp(const struct mg_str str1, const struct mg_str str2) WEAK;
int mg_strcmp(const struct mg_str str1, const struct mg_str str2) {
    size_t i = 0;
    while (i < str1.len && i < str2.len) {
        if (str1.p[i] < str2.p[i]) return -1;
        if (str1.p[i] > str2.p[i]) return 1;
        i++;
    }
    if (i < str1.len) return 1;
    if (i < str2.len) return -1;
    return 0;
}

int mg_strncmp(const struct mg_str, const struct mg_str, size_t n) WEAK;
int mg_strncmp(const struct mg_str str1, const struct mg_str str2, size_t n) {
    struct mg_str s1 = str1;
    struct mg_str s2 = str2;

    if (s1.len > n) {
        s1.len = n;
    }
    if (s2.len > n) {
        s2.len = n;
    }
    return mg_strcmp(s1, s2);
}

void mg_strfree(struct mg_str *s) WEAK;
void mg_strfree(struct mg_str *s) {
    char *sp = (char *)s->p;
    s->p = NULL;
    s->len = 0;
    if (sp != NULL) free(sp);
}

const char *mg_strstr(const struct mg_str haystack,
    const struct mg_str needle) WEAK;
const char *mg_strstr(const struct mg_str haystack,
    const struct mg_str needle) {
    size_t i;
    if (needle.len > haystack.len) return NULL;
    for (i = 0; i <= haystack.len - needle.len; i++) {
        if (memcmp(haystack.p + i, needle.p, needle.len) == 0) {
            return haystack.p + i;
        }
    }
    return NULL;
}

struct mg_str mg_strstrip(struct mg_str s) WEAK;
struct mg_str mg_strstrip(struct mg_str s) {
    while (s.len > 0 && isspace((int)*s.p)) {
        s.p++;
        s.len--;
    }
    while (s.len > 0 && isspace((int) *(s.p + s.len - 1))) {
        s.len--;
    }
    return s;
}

int mg_str_starts_with(struct mg_str s, struct mg_str prefix) WEAK;
int mg_str_starts_with(struct mg_str s, struct mg_str prefix) {
    const struct mg_str sp = MG_MK_STR_N(s.p, prefix.len);
    if (s.len < prefix.len) return 0;
    return (mg_strcmp(sp, prefix) == 0);
}
#ifdef MG_MODULE_LINES
#line 1 "common/str_util.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef EXCLUDE_COMMON

 /* Amalgamated: #include "common/str_util.h" */
 /* Amalgamated: #include "common/mg_mem.h" */
 /* Amalgamated: #include "common/platform.h" */

#ifndef C_DISABLE_BUILTIN_SNPRINTF
#define C_DISABLE_BUILTIN_SNPRINTF 0
#endif

/* Amalgamated: #include "common/mg_mem.h" */

size_t c_strnlen(const char *s, size_t maxlen) WEAK;
size_t c_strnlen(const char *s, size_t maxlen) {
    size_t l = 0;
    for (; l < maxlen && s[l] != '\0'; l++) {
    }
    return l;
}

#define C_SNPRINTF_APPEND_CHAR(ch)       \
  do {                                   \
    if (i < (int) buf_size) buf[i] = ch; \
    i++;                                 \
  } while (0)

#define C_SNPRINTF_FLAG_ZERO 1

#if C_DISABLE_BUILTIN_SNPRINTF
int c_vsnprintf(char *buf, size_t buf_size, const char *fmt, va_list ap) WEAK;
int c_vsnprintf(char *buf, size_t buf_size, const char *fmt, va_list ap) {
    return vsnprintf(buf, buf_size, fmt, ap);
}
#else
static int c_itoa(char *buf, size_t buf_size, int64_t num, int base, int flags,
    int field_width) {
    char tmp[40];
    int i = 0, k = 0, neg = 0;

    if (num < 0) {
        neg++;
        num = -num;
    }

    /* Print into temporary buffer - in reverse order */
    do {
        int rem = num % base;
        if (rem < 10) {
            tmp[k++] = '0' + rem;
        }
        else {
            tmp[k++] = 'a' + (rem - 10);
        }
        num /= base;
    } while (num > 0);

    /* Zero padding */
    if (flags && C_SNPRINTF_FLAG_ZERO) {
        while (k < field_width && k < (int) sizeof(tmp) - 1) {
            tmp[k++] = '0';
        }
    }

    /* And sign */
    if (neg) {
        tmp[k++] = '-';
    }

    /* Now output */
    while (--k >= 0) {
        C_SNPRINTF_APPEND_CHAR(tmp[k]);
    }

    return i;
}

int c_vsnprintf(char *buf, size_t buf_size, const char *fmt, va_list ap) WEAK;
int c_vsnprintf(char *buf, size_t buf_size, const char *fmt, va_list ap) {
    int ch, i = 0, len_mod, flags, precision, field_width;

    while ((ch = *fmt++) != '\0') {
        if (ch != '%') {
            C_SNPRINTF_APPEND_CHAR(ch);
        }
        else {
            /*
             * Conversion specification:
             *   zero or more flags (one of: # 0 - <space> + ')
             *   an optional minimum  field  width (digits)
             *   an  optional precision (. followed by digits, or *)
             *   an optional length modifier (one of: hh h l ll L q j z t)
             *   conversion specifier (one of: d i o u x X e E f F g G a A c s p n)
             */
            flags = field_width = precision = len_mod = 0;

            /* Flags. only zero-pad flag is supported. */
            if (*fmt == '0') {
                flags |= C_SNPRINTF_FLAG_ZERO;
            }

            /* Field width */
            while (*fmt >= '0' && *fmt <= '9') {
                field_width *= 10;
                field_width += *fmt++ - '0';
            }
            /* Dynamic field width */
            if (*fmt == '*') {
                field_width = va_arg(ap, int);
                fmt++;
            }

            /* Precision */
            if (*fmt == '.') {
                fmt++;
                if (*fmt == '*') {
                    precision = va_arg(ap, int);
                    fmt++;
                }
                else {
                    while (*fmt >= '0' && *fmt <= '9') {
                        precision *= 10;
                        precision += *fmt++ - '0';
                    }
                }
            }

            /* Length modifier */
            switch (*fmt) {
            case 'h':
            case 'l':
            case 'L':
            case 'I':
            case 'q':
            case 'j':
            case 'z':
            case 't':
                len_mod = *fmt++;
                if (*fmt == 'h') {
                    len_mod = 'H';
                    fmt++;
                }
                if (*fmt == 'l') {
                    len_mod = 'q';
                    fmt++;
                }
                break;
            }

            ch = *fmt++;
            if (ch == 's') {
                const char *s = va_arg(ap, const char *); /* Always fetch parameter */
                int j;
                int pad = field_width - (precision >= 0 ? c_strnlen(s, precision) : 0);
                for (j = 0; j < pad; j++) {
                    C_SNPRINTF_APPEND_CHAR(' ');
                }

                /* `s` may be NULL in case of %.*s */
                if (s != NULL) {
                    /* Ignore negative and 0 precisions */
                    for (j = 0; (precision <= 0 || j < precision) && s[j] != '\0'; j++) {
                        C_SNPRINTF_APPEND_CHAR(s[j]);
                    }
                }
            }
            else if (ch == 'c') {
                ch = va_arg(ap, int); /* Always fetch parameter */
                C_SNPRINTF_APPEND_CHAR(ch);
            }
            else if (ch == 'd' && len_mod == 0) {
                i += c_itoa(buf + i, buf_size - i, va_arg(ap, int), 10, flags,
                    field_width);
            }
            else if (ch == 'd' && len_mod == 'l') {
                i += c_itoa(buf + i, buf_size - i, va_arg(ap, long), 10, flags,
                    field_width);
#ifdef SSIZE_MAX
            }
            else if (ch == 'd' && len_mod == 'z') {
                i += c_itoa(buf + i, buf_size - i, va_arg(ap, ssize_t), 10, flags,
                    field_width);
#endif
            }
            else if (ch == 'd' && len_mod == 'q') {
                i += c_itoa(buf + i, buf_size - i, va_arg(ap, int64_t), 10, flags,
                    field_width);
            }
            else if ((ch == 'x' || ch == 'u') && len_mod == 0) {
                i += c_itoa(buf + i, buf_size - i, va_arg(ap, unsigned),
                    ch == 'x' ? 16 : 10, flags, field_width);
            }
            else if ((ch == 'x' || ch == 'u') && len_mod == 'l') {
                i += c_itoa(buf + i, buf_size - i, va_arg(ap, unsigned long),
                    ch == 'x' ? 16 : 10, flags, field_width);
            }
            else if ((ch == 'x' || ch == 'u') && len_mod == 'z') {
                i += c_itoa(buf + i, buf_size - i, va_arg(ap, size_t),
                    ch == 'x' ? 16 : 10, flags, field_width);
            }
            else if (ch == 'p') {
                unsigned long num = (unsigned long)(uintptr_t)va_arg(ap, void *);
                C_SNPRINTF_APPEND_CHAR('0');
                C_SNPRINTF_APPEND_CHAR('x');
                i += c_itoa(buf + i, buf_size - i, num, 16, flags, 0);
            }
            else {
#ifndef NO_LIBC
                /*
                 * TODO(lsm): abort is not nice in a library, remove it
                 * Also, ESP8266 SDK doesn't have it
                 */
                abort();
#endif
            }
        }
    }

    /* Zero-terminate the result */
    if (buf_size > 0) {
        buf[i < (int)buf_size ? i : (int)buf_size - 1] = '\0';
    }

    return i;
}
#endif

int c_snprintf(char *buf, size_t buf_size, const char *fmt, ...) WEAK;
int c_snprintf(char *buf, size_t buf_size, const char *fmt, ...) {
    int result;
    va_list ap;
    va_start(ap, fmt);
    result = c_vsnprintf(buf, buf_size, fmt, ap);
    va_end(ap);
    return result;
}

#ifdef _WIN32
int to_wchar(const char *path, wchar_t *wbuf, size_t wbuf_len) {
    int ret;
    char buf[MAX_PATH * 2], buf2[MAX_PATH * 2], *p;

    strncpy(buf, path, sizeof(buf));
    buf[sizeof(buf) - 1] = '\0';

    /* Trim trailing slashes. Leave backslash for paths like "X:\" */
    p = buf + strlen(buf) - 1;
    while (p > buf && p[-1] != ':' && (p[0] == '\\' || p[0] == '/')) *p-- = '\0';

    memset(wbuf, 0, wbuf_len * sizeof(wchar_t));
    ret = MultiByteToWideChar(CP_UTF8, 0, buf, -1, wbuf, (int)wbuf_len);

    /*
     * Convert back to Unicode. If doubly-converted string does not match the
     * original, something is fishy, reject.
     */
    WideCharToMultiByte(CP_UTF8, 0, wbuf, (int)wbuf_len, buf2, sizeof(buf2),
        NULL, NULL);
    if (strcmp(buf, buf2) != 0) {
        wbuf[0] = L'\0';
        ret = 0;
    }

    return ret;
}
#endif /* _WIN32 */

/* The simplest O(mn) algorithm. Better implementation are GPLed */
const char *c_strnstr(const char *s, const char *find, size_t slen) WEAK;
const char *c_strnstr(const char *s, const char *find, size_t slen) {
    size_t find_length = strlen(find);
    size_t i;

    for (i = 0; i < slen; i++) {
        if (i + find_length > slen) {
            return NULL;
        }

        if (strncmp(&s[i], find, find_length) == 0) {
            return &s[i];
        }
    }

    return NULL;
}

#if CS_ENABLE_STRDUP
char *strdup(const char *src) WEAK;
char *strdup(const char *src) {
    size_t len = strlen(src) + 1;
    char *ret = MG_MALLOC(len);
    if (ret != NULL) {
        strcpy(ret, src);
    }
    return ret;
}
#endif

void cs_to_hex(char *to, const unsigned char *p, size_t len) WEAK;
void cs_to_hex(char *to, const unsigned char *p, size_t len) {
    static const char *hex = "0123456789abcdef";

    for (; len--; p++) {
        *to++ = hex[p[0] >> 4];
        *to++ = hex[p[0] & 0x0f];
    }
    *to = '\0';
}

static int fourbit(int ch) {
    if (ch >= '0' && ch <= '9') {
        return ch - '0';
    }
    else if (ch >= 'a' && ch <= 'f') {
        return ch - 'a' + 10;
    }
    else if (ch >= 'A' && ch <= 'F') {
        return ch - 'A' + 10;
    }
    return 0;
}

void cs_from_hex(char *to, const char *p, size_t len) WEAK;
void cs_from_hex(char *to, const char *p, size_t len) {
    size_t i;

    for (i = 0; i < len; i += 2) {
        *to++ = (fourbit(p[i]) << 4) + fourbit(p[i + 1]);
    }
    *to = '\0';
}

#if CS_ENABLE_TO64
int64_t cs_to64(const char *s) WEAK;
int64_t cs_to64(const char *s) {
    int64_t result = 0;
    int64_t neg = 1;
    while (*s && isspace((unsigned char)*s)) s++;
    if (*s == '-') {
        neg = -1;
        s++;
    }
    while (isdigit((unsigned char)*s)) {
        result *= 10;
        result += (*s - '0');
        s++;
    }
    return result * neg;
}
#endif

static int str_util_lowercase(const char *s) {
    return tolower(*(const unsigned char *)s);
}

int mg_ncasecmp(const char *s1, const char *s2, size_t len) WEAK;
int mg_ncasecmp(const char *s1, const char *s2, size_t len) {
    int diff = 0;

    if (len > 0) do {
        diff = str_util_lowercase(s1++) - str_util_lowercase(s2++);
    } while (diff == 0 && s1[-1] != '\0' && --len > 0);

    return diff;
}

int mg_casecmp(const char *s1, const char *s2) WEAK;
int mg_casecmp(const char *s1, const char *s2) {
    return mg_ncasecmp(s1, s2, (size_t)~0);
}

int mg_asprintf(char **buf, size_t size, const char *fmt, ...) WEAK;
int mg_asprintf(char **buf, size_t size, const char *fmt, ...) {
    int ret;
    va_list ap;
    va_start(ap, fmt);
    ret = mg_avprintf(buf, size, fmt, ap);
    va_end(ap);
    return ret;
}

int mg_avprintf(char **buf, size_t size, const char *fmt, va_list ap) WEAK;
int mg_avprintf(char **buf, size_t size, const char *fmt, va_list ap) {
    va_list ap_copy;
    int len;

    va_copy(ap_copy, ap);
    len = vsnprintf(*buf, size, fmt, ap_copy);
    va_end(ap_copy);

    if (len < 0) {
        /* eCos and Windows are not standard-compliant and return -1 when
         * the buffer is too small. Keep allocating larger buffers until we
         * succeed or out of memory. */
        *buf = NULL; /* LCOV_EXCL_START */
        while (len < 0) {
            MG_FREE(*buf);
            if (size == 0) {
                size = 5;
            }
            size *= 2;
            if ((*buf = (char *)MG_MALLOC(size)) == NULL) {
                len = -1;
                break;
            }
            va_copy(ap_copy, ap);
            len = vsnprintf(*buf, size - 1, fmt, ap_copy);
            va_end(ap_copy);
        }

        /*
         * Microsoft version of vsnprintf() is not always null-terminated, so put
         * the terminator manually
         */
        (*buf)[len] = 0;
        /* LCOV_EXCL_STOP */
    }
    else if (len >= (int)size) {
        /* Standard-compliant code path. Allocate a buffer that is large enough. */
        if ((*buf = (char *)MG_MALLOC(len + 1)) == NULL) {
            len = -1; /* LCOV_EXCL_LINE */
        }
        else {    /* LCOV_EXCL_LINE */
            va_copy(ap_copy, ap);
            len = vsnprintf(*buf, len + 1, fmt, ap_copy);
            va_end(ap_copy);
        }
    }

    return len;
}

const char *mg_next_comma_list_entry(const char *, struct mg_str *,
    struct mg_str *) WEAK;
const char *mg_next_comma_list_entry(const char *list, struct mg_str *val,
    struct mg_str *eq_val) {
    struct mg_str ret = mg_next_comma_list_entry_n(mg_mk_str(list), val, eq_val);
    return ret.p;
}

struct mg_str mg_next_comma_list_entry_n(struct mg_str list, struct mg_str *val,
    struct mg_str *eq_val) WEAK;
struct mg_str mg_next_comma_list_entry_n(struct mg_str list, struct mg_str *val,
    struct mg_str *eq_val) {
    if (list.len == 0) {
        /* End of the list */
        list = mg_mk_str(NULL);
    }
    else {
        const char *chr = NULL;
        *val = list;

        if ((chr = mg_strchr(*val, ',')) != NULL) {
            /* Comma found. Store length and shift the list ptr */
            val->len = chr - val->p;
            chr++;
            list.len -= (chr - list.p);
            list.p = chr;
        }
        else {
            /* This value is the last one */
            list = mg_mk_str_n(list.p + list.len, 0);
        }

        if (eq_val != NULL) {
            /* Value has form "x=y", adjust pointers and lengths */
            /* so that val points to "x", and eq_val points to "y". */
            eq_val->len = 0;
            eq_val->p = (const char *)memchr(val->p, '=', val->len);
            if (eq_val->p != NULL) {
                eq_val->p++; /* Skip over '=' character */
                eq_val->len = val->p + val->len - eq_val->p;
                val->len = (eq_val->p - val->p) - 1;
            }
        }
    }

    return list;
}

size_t mg_match_prefix_n(const struct mg_str, const struct mg_str) WEAK;
size_t mg_match_prefix_n(const struct mg_str pattern, const struct mg_str str) {
    const char *or_str;
    size_t res = 0, len = 0, i = 0, j = 0;

    if ((or_str = (const char *)memchr(pattern.p, '|', pattern.len)) != NULL ||
        (or_str = (const char *)memchr(pattern.p, ',', pattern.len)) != NULL) {
        struct mg_str pstr = { pattern.p, (size_t)(or_str - pattern.p) };
        res = mg_match_prefix_n(pstr, str);
        if (res > 0) return res;
        pstr.p = or_str + 1;
        pstr.len = (pattern.p + pattern.len) - (or_str + 1);
        return mg_match_prefix_n(pstr, str);
    }

    for (; i < pattern.len && j < str.len; i++, j++) {
        if (pattern.p[i] == '?') {
            continue;
        }
        else if (pattern.p[i] == '*') {
            i++;
            if (i < pattern.len && pattern.p[i] == '*') {
                i++;
                len = str.len - j;
            }
            else {
                len = 0;
                while (j + len < str.len && str.p[j + len] != '/') len++;
            }
            if (i == pattern.len || (pattern.p[i] == '$' && i == pattern.len - 1))
                return j + len;
            do {
                const struct mg_str pstr = { pattern.p + i, pattern.len - i };
                const struct mg_str sstr = { str.p + j + len, str.len - j - len };
                res = mg_match_prefix_n(pstr, sstr);
            } while (res == 0 && len != 0 && len-- > 0);
            return res == 0 ? 0 : j + res + len;
        }
        else if (str_util_lowercase(&pattern.p[i]) !=
            str_util_lowercase(&str.p[j])) {
            break;
        }
    }
    if (i < pattern.len && pattern.p[i] == '$') {
        return j == str.len ? str.len : 0;
    }
    return i == pattern.len ? j : 0;
}

size_t mg_match_prefix(const char *, int, const char *) WEAK;
size_t mg_match_prefix(const char *pattern, int pattern_len, const char *str) {
    const struct mg_str pstr = { pattern, (size_t)pattern_len };
    struct mg_str s = { str, 0 };
    if (str != NULL) s.len = strlen(str);
    return mg_match_prefix_n(pstr, s);
}

#endif /* EXCLUDE_COMMON */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_net.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 *
 * This software is dual-licensed: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. For the terms of this
 * license, see <http://www.gnu.org/licenses/>.
 *
 * You are free to use this software under the terms of the GNU General
 * Public License, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * Alternatively, you can license this software under a commercial
 * license, as set out in <https://www.cesanta.com/license>.
 */

 /* Amalgamated: #include "common/cs_time.h" */
 /* Amalgamated: #include "mg_dns.h" */
 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "mg_resolv.h" */
 /* Amalgamated: #include "mg_util.h" */

#define MG_MAX_HOST_LEN 200

#ifndef MG_TCP_IO_SIZE
#define MG_TCP_IO_SIZE 1460
#endif
#ifndef MG_UDP_IO_SIZE
#define MG_UDP_IO_SIZE 1460
#endif

#define MG_COPY_COMMON_CONNECTION_OPTIONS(dst, src) \
  memcpy(dst, src, sizeof(*dst));

/* Which flags can be pre-set by the user at connection creation time. */
#define _MG_ALLOWED_CONNECT_FLAGS_MASK                                   \
  (MG_F_USER_1 | MG_F_USER_2 | MG_F_USER_3 | MG_F_USER_4 | MG_F_USER_5 | \
   MG_F_USER_6 | MG_F_WEBSOCKET_NO_DEFRAG | MG_F_ENABLE_BROADCAST)
/* Which flags should be modifiable by user's callbacks. */
#define _MG_CALLBACK_MODIFIABLE_FLAGS_MASK                               \
  (MG_F_USER_1 | MG_F_USER_2 | MG_F_USER_3 | MG_F_USER_4 | MG_F_USER_5 | \
   MG_F_USER_6 | MG_F_WEBSOCKET_NO_DEFRAG | MG_F_SEND_AND_CLOSE |        \
   MG_F_CLOSE_IMMEDIATELY | MG_F_IS_WEBSOCKET | MG_F_DELETE_CHUNK)

#ifndef intptr_t
#define intptr_t long
#endif

MG_INTERNAL void mg_add_conn(struct mg_mgr *mgr, struct mg_connection *c) {
    DBG(("%p %p", mgr, c));
    c->mgr = mgr;
    c->next = mgr->active_connections;
    mgr->active_connections = c;
    c->prev = NULL;
    if (c->next != NULL) c->next->prev = c;
    if (c->sock != INVALID_SOCKET) {
        c->iface->vtable->add_conn(c);
    }
}

MG_INTERNAL void mg_remove_conn(struct mg_connection *conn) {
    if (conn->prev == NULL) conn->mgr->active_connections = conn->next;
    if (conn->prev) conn->prev->next = conn->next;
    if (conn->next) conn->next->prev = conn->prev;
    conn->prev = conn->next = NULL;
    conn->iface->vtable->remove_conn(conn);
}

MG_INTERNAL void mg_call(struct mg_connection *nc,
    mg_event_handler_t ev_handler, void *user_data, int ev,
    void *ev_data) {
    if (ev_handler == NULL) {
        /*
         * If protocol handler is specified, call it. Otherwise, call user-specified
         * event handler.
         */
        ev_handler = nc->proto_handler ? nc->proto_handler : nc->handler;
    }
    if (ev != MG_EV_POLL) {
        DBG(("%p %s ev=%d ev_data=%p flags=0x%lx rmbl=%d smbl=%d", nc,
            ev_handler == nc->handler ? "user" : "proto", ev, ev_data, nc->flags,
            (int)nc->recv_mbuf.len, (int)nc->send_mbuf.len));
    }

#if !defined(NO_LIBC) && MG_ENABLE_HEXDUMP
    if (nc->mgr->hexdump_file != NULL && ev != MG_EV_POLL && ev != MG_EV_RECV &&
        ev != MG_EV_SEND /* handled separately */) {
        mg_hexdump_connection(nc, nc->mgr->hexdump_file, NULL, 0, ev);
    }
#endif
    if (ev_handler != NULL) {
        unsigned long flags_before = nc->flags;
        ev_handler(nc, ev, ev_data MG_UD_ARG(user_data));
        /* Prevent user handler from fiddling with system flags. */
        if (ev_handler == nc->handler && nc->flags != flags_before) {
            nc->flags = (flags_before & ~_MG_CALLBACK_MODIFIABLE_FLAGS_MASK) |
                (nc->flags & _MG_CALLBACK_MODIFIABLE_FLAGS_MASK);
        }
    }
    if (ev != MG_EV_POLL) nc->mgr->num_calls++;
    if (ev != MG_EV_POLL) {
        DBG(("%p after %s flags=0x%lx rmbl=%d smbl=%d", nc,
            ev_handler == nc->handler ? "user" : "proto", nc->flags,
            (int)nc->recv_mbuf.len, (int)nc->send_mbuf.len));
    }
#if !MG_ENABLE_CALLBACK_USERDATA
    (void) user_data;
#endif
}

MG_INTERNAL void mg_timer(struct mg_connection *c, double now) {
    if (c->ev_timer_time > 0 && now >= c->ev_timer_time) {
        double old_value = c->ev_timer_time;
        c->ev_timer_time = 0;
        mg_call(c, NULL, c->user_data, MG_EV_TIMER, &old_value);
    }
}

MG_INTERNAL size_t recv_avail_size(struct mg_connection *conn, size_t max) {
    size_t avail;
    if (conn->recv_mbuf_limit < conn->recv_mbuf.len) return 0;
    avail = conn->recv_mbuf_limit - conn->recv_mbuf.len;
    return avail > max ? max : avail;
}

static int mg_do_recv(struct mg_connection *nc);

int mg_if_poll(struct mg_connection *nc, double now) {
    if (nc->flags & MG_F_CLOSE_IMMEDIATELY) {
        mg_close_conn(nc);
        return 0;
    }
    else if (nc->flags & MG_F_SEND_AND_CLOSE) {
        if (nc->send_mbuf.len == 0) {
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
            mg_close_conn(nc);
            return 0;
        }
    }
    else if (nc->flags & MG_F_RECV_AND_CLOSE) {
        mg_close_conn(nc);
        return 0;
    }
#if MG_ENABLE_SSL
    if ((nc->flags & (MG_F_SSL | MG_F_LISTENING | MG_F_CONNECTING)) == MG_F_SSL) {
        /* SSL library may have data to be delivered to the app in its buffers,
         * drain them. */
        int recved = 0;
        do {
            if (nc->flags & (MG_F_WANT_READ | MG_F_WANT_WRITE)) break;
            if (recv_avail_size(nc, MG_TCP_IO_SIZE) <= 0) break;
            recved = mg_do_recv(nc);
        } while (recved > 0);
    }
#endif /* MG_ENABLE_SSL */
    mg_timer(nc, now);
    {
        time_t now_t = (time_t)now;
        mg_call(nc, NULL, nc->user_data, MG_EV_POLL, &now_t);
    }
    return 1;
}

void mg_destroy_conn(struct mg_connection *conn, int destroy_if) {
    if (conn->sock != INVALID_SOCKET) { /* Don't print timer-only conns */
        LOG(LL_DEBUG, ("%p 0x%lx %d", conn, conn->flags, destroy_if));
    }
    if (destroy_if) conn->iface->vtable->destroy_conn(conn);
    if (conn->proto_data != NULL && conn->proto_data_destructor != NULL) {
        conn->proto_data_destructor(conn->proto_data);
    }
#if MG_ENABLE_SSL
    mg_ssl_if_conn_free(conn);
#endif
    mbuf_free(&conn->recv_mbuf);
    mbuf_free(&conn->send_mbuf);

    memset(conn, 0, sizeof(*conn));
    MG_FREE(conn);
}

void mg_close_conn(struct mg_connection *conn) {
    /* See if there's any remaining data to deliver. Skip if user completely
     * throttled the connection there will be no progress anyway. */
    if (conn->sock != INVALID_SOCKET && mg_do_recv(conn) == -2) {
        /* Receive is throttled, wait. */
        conn->flags |= MG_F_RECV_AND_CLOSE;
        return;
    }
#if MG_ENABLE_SSL
    if (conn->flags & MG_F_SSL_HANDSHAKE_DONE) {
        mg_ssl_if_conn_close_notify(conn);
    }
#endif
    /*
     * Clearly mark the connection as going away (if not already).
     * Some net_if impls (LwIP) need this for cleanly handling half-dead conns.
     */
    conn->flags |= MG_F_CLOSE_IMMEDIATELY;
    mg_remove_conn(conn);
    conn->iface->vtable->destroy_conn(conn);
    mg_call(conn, NULL, conn->user_data, MG_EV_CLOSE, NULL);
    mg_destroy_conn(conn, 0 /* destroy_if */);
}

void mg_mgr_init(struct mg_mgr *m, void *user_data) {
    struct mg_mgr_init_opts opts;
    memset(&opts, 0, sizeof(opts));
    mg_mgr_init_opt(m, user_data, opts);
}

void mg_mgr_init_opt(struct mg_mgr *m, void *user_data,
    struct mg_mgr_init_opts opts) {
    memset(m, 0, sizeof(*m));
#if MG_ENABLE_BROADCAST
    m->ctl[0] = m->ctl[1] = INVALID_SOCKET;
#endif
    m->user_data = user_data;

#ifdef _WIN32
    {
        WSADATA data;
        WSAStartup(MAKEWORD(2, 2), &data);
    }
#elif defined(__unix__)
    /* Ignore SIGPIPE signal, so if client cancels the request, it
     * won't kill the whole process. */
    signal(SIGPIPE, SIG_IGN);
#endif

    {
        int i;
        if (opts.num_ifaces == 0) {
            opts.num_ifaces = mg_num_ifaces;
            opts.ifaces = mg_ifaces;
        }
        if (opts.main_iface != NULL) {
            opts.ifaces[MG_MAIN_IFACE] = opts.main_iface;
        }
        m->num_ifaces = opts.num_ifaces;
        m->ifaces =
            (struct mg_iface **) MG_MALLOC(sizeof(*m->ifaces) * opts.num_ifaces);
        for (i = 0; i < opts.num_ifaces; i++) {
            m->ifaces[i] = mg_if_create_iface(opts.ifaces[i], m);
            m->ifaces[i]->vtable->init(m->ifaces[i]);
        }
    }
    if (opts.nameserver != NULL) {
        m->nameserver = strdup(opts.nameserver);
    }
    DBG(("=================================="));
    DBG(("init mgr=%p", m));
#if MG_ENABLE_SSL
    {
        static int init_done;
        if (!init_done) {
            mg_ssl_if_init();
            init_done++;
        }
    }
#endif
}

void mg_mgr_free(struct mg_mgr *m) {
    struct mg_connection *conn, *tmp_conn;

    DBG(("%p", m));
    if (m == NULL) return;
    /* Do one last poll, see https://github.com/cesanta/mongoose/issues/286 */
    mg_mgr_poll(m, 0);

#if MG_ENABLE_BROADCAST
    if (m->ctl[0] != INVALID_SOCKET) closesocket(m->ctl[0]);
    if (m->ctl[1] != INVALID_SOCKET) closesocket(m->ctl[1]);
    m->ctl[0] = m->ctl[1] = INVALID_SOCKET;
#endif

    for (conn = m->active_connections; conn != NULL; conn = tmp_conn) {
        tmp_conn = conn->next;
        conn->flags |= MG_F_CLOSE_IMMEDIATELY;
        mg_close_conn(conn);
    }

    {
        int i;
        for (i = 0; i < m->num_ifaces; i++) {
            m->ifaces[i]->vtable->free(m->ifaces[i]);
            MG_FREE(m->ifaces[i]);
        }
        MG_FREE(m->ifaces);
    }

    MG_FREE((char *)m->nameserver);
}

int mg_mgr_poll(struct mg_mgr *m, int timeout_ms) {
    int i, num_calls_before = m->num_calls;

    for (i = 0; i < m->num_ifaces; i++) {
        m->ifaces[i]->vtable->poll(m->ifaces[i], timeout_ms);
    }

    return (m->num_calls - num_calls_before);
}

int mg_vprintf(struct mg_connection *nc, const char *fmt, va_list ap) {
    char mem[MG_VPRINTF_BUFFER_SIZE], *buf = mem;
    int len;

    if ((len = mg_avprintf(&buf, sizeof(mem), fmt, ap)) > 0) {
        mg_send(nc, buf, len);
    }
    if (buf != mem && buf != NULL) {
        MG_FREE(buf); /* LCOV_EXCL_LINE */
    }               /* LCOV_EXCL_LINE */

    return len;
}

int mg_printf(struct mg_connection *conn, const char *fmt, ...) {
    int len;
    va_list ap;
    va_start(ap, fmt);
    len = mg_vprintf(conn, fmt, ap);
    va_end(ap);
    return len;
}

#if MG_ENABLE_SYNC_RESOLVER
/* TODO(lsm): use non-blocking resolver */
static int mg_resolve2(const char *host, struct in_addr *ina) {
#if MG_ENABLE_GETADDRINFO
    int rv = 0;
    struct addrinfo hints, *servinfo, *p;
    struct sockaddr_in *h = NULL;
    memset(&hints, 0, sizeof hints);
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
    if ((rv = getaddrinfo(host, NULL, NULL, &servinfo)) != 0) {
        DBG(("getaddrinfo(%s) failed: %s", host, strerror(mg_get_errno())));
        return 0;
    }
    for (p = servinfo; p != NULL; p = p->ai_next) {
        memcpy(&h, &p->ai_addr, sizeof(h));
        memcpy(ina, &h->sin_addr, sizeof(*ina));
    }
    freeaddrinfo(servinfo);
    return 1;
#else
    struct hostent *he;
    if ((he = gethostbyname(host)) == NULL) {
        DBG(("gethostbyname(%s) failed: %s", host, strerror(mg_get_errno())));
    }
    else {
        memcpy(ina, he->h_addr_list[0], sizeof(*ina));
        return 1;
    }
    return 0;
#endif /* MG_ENABLE_GETADDRINFO */
}

int mg_resolve(const char *host, char *buf, size_t n) {
    struct in_addr ad;
    return mg_resolve2(host, &ad) ? snprintf(buf, n, "%s", inet_ntoa(ad)) : 0;
}
#endif /* MG_ENABLE_SYNC_RESOLVER */

MG_INTERNAL struct mg_connection *mg_create_connection_base(
    struct mg_mgr *mgr, mg_event_handler_t callback,
    struct mg_add_sock_opts opts) {
    struct mg_connection *conn;

    if ((conn = (struct mg_connection *) MG_CALLOC(1, sizeof(*conn))) != NULL) {
        conn->sock = INVALID_SOCKET;
        conn->handler = callback;
        conn->mgr = mgr;
        conn->last_io_time = (time_t)mg_time();
        conn->iface =
            (opts.iface != NULL ? opts.iface : mgr->ifaces[MG_MAIN_IFACE]);
        conn->flags = opts.flags & _MG_ALLOWED_CONNECT_FLAGS_MASK;
        conn->user_data = opts.user_data;
        /*
         * SIZE_MAX is defined as a long long constant in
         * system headers on some platforms and so it
         * doesn't compile with pedantic ansi flags.
         */
        conn->recv_mbuf_limit = ~0;
    }
    else {
        MG_SET_PTRPTR(opts.error_string, "failed to create connection");
    }

    return conn;
}

MG_INTERNAL struct mg_connection *mg_create_connection(
    struct mg_mgr *mgr, mg_event_handler_t callback,
    struct mg_add_sock_opts opts) {
    struct mg_connection *conn = mg_create_connection_base(mgr, callback, opts);

    if (conn != NULL && !conn->iface->vtable->create_conn(conn)) {
        MG_FREE(conn);
        conn = NULL;
    }
    if (conn == NULL) {
        MG_SET_PTRPTR(opts.error_string, "failed to init connection");
    }

    return conn;
}

/*
 * Address format: [PROTO://][HOST]:PORT
 *
 * HOST could be IPv4/IPv6 address or a host name.
 * `host` is a destination buffer to hold parsed HOST part. Should be at least
 * MG_MAX_HOST_LEN bytes long.
 * `proto` is a returned socket type, either SOCK_STREAM or SOCK_DGRAM
 *
 * Return:
 *   -1   on parse error
 *    0   if HOST needs DNS lookup
 *   >0   length of the address string
 */
MG_INTERNAL int mg_parse_address(const char *str, union socket_address *sa,
    int *proto, char *host, size_t host_len) {
    unsigned int a, b, c, d, port = 0;
    int ch, len = 0;
#if MG_ENABLE_IPV6
    char buf[100];
#endif

    /*
     * MacOS needs that. If we do not zero it, subsequent bind() will fail.
     * Also, all-zeroes in the socket address means binding to all addresses
     * for both IPv4 and IPv6 (INADDR_ANY and IN6ADDR_ANY_INIT).
     */
    memset(sa, 0, sizeof(*sa));
    sa->sin.sin_family = AF_INET;

    *proto = SOCK_STREAM;

    if (strncmp(str, "udp://", 6) == 0) {
        str += 6;
        *proto = SOCK_DGRAM;
    }
    else if (strncmp(str, "tcp://", 6) == 0) {
        str += 6;
    }

    if (sscanf(str, "%u.%u.%u.%u:%u%n", &a, &b, &c, &d, &port, &len) == 5) {
        /* Bind to a specific IPv4 address, e.g. 192.168.1.5:8080 */
        sa->sin.sin_addr.s_addr =
            htonl(((uint32_t)a << 24) | ((uint32_t)b << 16) | c << 8 | d);
        sa->sin.sin_port = htons((uint16_t)port);
#if MG_ENABLE_IPV6
    }
    else if (sscanf(str, "[%99[^]]]:%u%n", buf, &port, &len) == 2 &&
        inet_pton(AF_INET6, buf, &sa->sin6.sin6_addr)) {
        /* IPv6 address, e.g. [3ffe:2a00:100:7031::1]:8080 */
        sa->sin6.sin6_family = AF_INET6;
        sa->sin.sin_port = htons((uint16_t)port);
#endif
#if MG_ENABLE_ASYNC_RESOLVER
    }
    else if (strlen(str) < host_len &&
        sscanf(str, "%[^ :]:%u%n", host, &port, &len) == 2) {
        sa->sin.sin_port = htons((uint16_t)port);
        if (mg_resolve_from_hosts_file(host, sa) != 0) {
            /*
             * if resolving from hosts file failed and the host
             * we are trying to resolve is `localhost` - we should
             * try to resolve it using `gethostbyname` and do not try
             * to resolve it via DNS server if gethostbyname has failed too
             */
            if (mg_ncasecmp(host, "localhost", 9) != 0) {
                return 0;
            }

#if MG_ENABLE_SYNC_RESOLVER
            if (!mg_resolve2(host, &sa->sin.sin_addr)) {
                return -1;
            }
#else
            return -1;
#endif
        }
#endif
    }
    else if (sscanf(str, ":%u%n", &port, &len) == 1 ||
        sscanf(str, "%u%n", &port, &len) == 1) {
        /* If only port is specified, bind to IPv4, INADDR_ANY */
        sa->sin.sin_port = htons((uint16_t)port);
    }
    else {
        return -1;
    }

    /* Required for MG_ENABLE_ASYNC_RESOLVER=0 */
    (void)host;
    (void)host_len;

    ch = str[len]; /* Character that follows the address */
    return port < 0xffffUL && (ch == '\0' || ch == ',' || isspace(ch)) ? len : -1;
}

#if MG_ENABLE_SSL
MG_INTERNAL void mg_ssl_handshake(struct mg_connection *nc) {
    int err = 0;
    int server_side = (nc->listener != NULL);
    enum mg_ssl_if_result res;
    if (nc->flags & MG_F_SSL_HANDSHAKE_DONE) return;
    res = mg_ssl_if_handshake(nc);

    if (res == MG_SSL_OK) {
        nc->flags |= MG_F_SSL_HANDSHAKE_DONE;
        nc->flags &= ~(MG_F_WANT_READ | MG_F_WANT_WRITE);
        if (server_side) {
            mg_call(nc, NULL, nc->user_data, MG_EV_ACCEPT, &nc->sa);
        }
        else {
            mg_call(nc, NULL, nc->user_data, MG_EV_CONNECT, &err);
        }
    }
    else if (res == MG_SSL_WANT_READ) {
        nc->flags |= MG_F_WANT_READ;
    }
    else if (res == MG_SSL_WANT_WRITE) {
        nc->flags |= MG_F_WANT_WRITE;
    }
    else {
        if (!server_side) {
            err = res;
            mg_call(nc, NULL, nc->user_data, MG_EV_CONNECT, &err);
        }
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
    }
}
#endif /* MG_ENABLE_SSL */

struct mg_connection *mg_if_accept_new_conn(struct mg_connection *lc) {
    struct mg_add_sock_opts opts;
    struct mg_connection *nc;
    memset(&opts, 0, sizeof(opts));
    nc = mg_create_connection(lc->mgr, lc->handler, opts);
    if (nc == NULL) return NULL;
    nc->listener = lc;
    nc->proto_handler = lc->proto_handler;
    nc->user_data = lc->user_data;
    nc->recv_mbuf_limit = lc->recv_mbuf_limit;
    nc->iface = lc->iface;
    if (lc->flags & MG_F_SSL) nc->flags |= MG_F_SSL;
    mg_add_conn(nc->mgr, nc);
    LOG(LL_DEBUG, ("%p %p %d %d", lc, nc, nc->sock, (int)nc->flags));
    return nc;
}

void mg_if_accept_tcp_cb(struct mg_connection *nc, union socket_address *sa,
    size_t sa_len) {
    LOG(LL_DEBUG, ("%p %s://%s:%hu", nc, (nc->flags & MG_F_UDP ? "udp" : "tcp"),
        inet_ntoa(sa->sin.sin_addr), ntohs(sa->sin.sin_port)));
    nc->sa = *sa;
#if MG_ENABLE_SSL
    if (nc->listener->flags & MG_F_SSL) {
        nc->flags |= MG_F_SSL;
        if (mg_ssl_if_conn_accept(nc, nc->listener) == MG_SSL_OK) {
            mg_ssl_handshake(nc);
        }
        else {
            mg_close_conn(nc);
        }
    }
    else
#endif
    {
        mg_call(nc, NULL, nc->user_data, MG_EV_ACCEPT, &nc->sa);
    }
    (void)sa_len;
}

void mg_send(struct mg_connection *nc, const void *buf, int len) {
    nc->last_io_time = (time_t)mg_time();
    mbuf_append(&nc->send_mbuf, buf, len);
}

static int mg_recv_tcp(struct mg_connection *nc, char *buf, size_t len);
static int mg_recv_udp(struct mg_connection *nc, char *buf, size_t len);

static int mg_do_recv(struct mg_connection *nc) {
    int res = 0;
    char *buf = NULL;
    size_t len = (nc->flags & MG_F_UDP ? MG_UDP_IO_SIZE : MG_TCP_IO_SIZE);
    if ((nc->flags & (MG_F_CLOSE_IMMEDIATELY | MG_F_CONNECTING)) ||
        ((nc->flags & MG_F_LISTENING) && !(nc->flags & MG_F_UDP))) {
        return -1;
    }
    do {
        len = recv_avail_size(nc, len);
        if (len == 0) {
            res = -2;
            break;
        }
        if (nc->recv_mbuf.size < nc->recv_mbuf.len + len) {
            mbuf_resize(&nc->recv_mbuf, nc->recv_mbuf.len + len);
        }
        buf = nc->recv_mbuf.buf + nc->recv_mbuf.len;
        len = nc->recv_mbuf.size - nc->recv_mbuf.len;
        if (nc->flags & MG_F_UDP) {
            res = mg_recv_udp(nc, buf, len);
        }
        else {
            res = mg_recv_tcp(nc, buf, len);
        }
    } while (res > 0 && !(nc->flags & (MG_F_CLOSE_IMMEDIATELY | MG_F_UDP)));
    return res;
}

void mg_if_can_recv_cb(struct mg_connection *nc) {
    mg_do_recv(nc);
}

static int mg_recv_tcp(struct mg_connection *nc, char *buf, size_t len) {
    int n = 0;
#if MG_ENABLE_SSL
    if (nc->flags & MG_F_SSL) {
        if (nc->flags & MG_F_SSL_HANDSHAKE_DONE) {
            n = mg_ssl_if_read(nc, buf, len);
            DBG(("%p <- %d bytes (SSL)", nc, n));
            if (n < 0) {
                if (n == MG_SSL_WANT_READ) {
                    nc->flags |= MG_F_WANT_READ;
                    n = 0;
                }
                else {
                    nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                }
            }
            else if (n > 0) {
                nc->flags &= ~MG_F_WANT_READ;
            }
        }
        else {
            mg_ssl_handshake(nc);
        }
    }
    else
#endif
    {
        n = nc->iface->vtable->tcp_recv(nc, buf, len);
        DBG(("%p <- %d bytes", nc, n));
    }
    if (n > 0) {
        nc->recv_mbuf.len += n;
        nc->last_io_time = (time_t)mg_time();
#if !defined(NO_LIBC) && MG_ENABLE_HEXDUMP
        if (nc->mgr && nc->mgr->hexdump_file != NULL) {
            mg_hexdump_connection(nc, nc->mgr->hexdump_file, buf, n, MG_EV_RECV);
        }
#endif
        mbuf_trim(&nc->recv_mbuf);
        mg_call(nc, NULL, nc->user_data, MG_EV_RECV, &n);
    }
    else if (n < 0) {
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
    }
    mbuf_trim(&nc->recv_mbuf);
    return n;
}

static int mg_recv_udp(struct mg_connection *nc, char *buf, size_t len) {
    int n = 0;
    struct mg_connection *lc = nc;
    union socket_address sa;
    size_t sa_len = sizeof(sa);
    n = nc->iface->vtable->udp_recv(lc, buf, len, &sa, &sa_len);
    if (n < 0) {
        lc->flags |= MG_F_CLOSE_IMMEDIATELY;
        goto out;
    }
    if (nc->flags & MG_F_LISTENING) {
        /*
         * Do we have an existing connection for this source?
         * This is very inefficient for long connection lists.
         */
        lc = nc;
        for (nc = mg_next(lc->mgr, NULL); nc != NULL; nc = mg_next(lc->mgr, nc)) {
            if (memcmp(&nc->sa.sa, &sa.sa, sa_len) == 0 && nc->listener == lc) {
                break;
            }
        }
        if (nc == NULL) {
            struct mg_add_sock_opts opts;
            memset(&opts, 0, sizeof(opts));
            /* Create fake connection w/out sock initialization */
            nc = mg_create_connection_base(lc->mgr, lc->handler, opts);
            if (nc != NULL) {
                nc->sock = lc->sock;
                nc->listener = lc;
                nc->sa = sa;
                nc->proto_handler = lc->proto_handler;
                nc->user_data = lc->user_data;
                nc->recv_mbuf_limit = lc->recv_mbuf_limit;
                nc->flags = MG_F_UDP;
                /*
                 * Long-lived UDP "connections" i.e. interactions that involve more
                 * than one request and response are rare, most are transactional:
                 * response is sent and the "connection" is closed. Or - should be.
                 * But users (including ourselves) tend to forget about that part,
                 * because UDP is connectionless and one does not think about
                 * processing a UDP request as handling a connection that needs to be
                 * closed. Thus, we begin with SEND_AND_CLOSE flag set, which should
                 * be a reasonable default for most use cases, but it is possible to
                 * turn it off the connection should be kept alive after processing.
                 */
                nc->flags |= MG_F_SEND_AND_CLOSE;
                mg_add_conn(lc->mgr, nc);
                mg_call(nc, NULL, nc->user_data, MG_EV_ACCEPT, &nc->sa);
            }
        }
    }
    if (nc != NULL) {
        DBG(("%p <- %d bytes from %s:%d", nc, n, inet_ntoa(nc->sa.sin.sin_addr),
            ntohs(nc->sa.sin.sin_port)));
        if (nc == lc) {
            nc->recv_mbuf.len += n;
        }
        else {
            mbuf_append(&nc->recv_mbuf, buf, n);
        }
        mbuf_trim(&lc->recv_mbuf);
        lc->last_io_time = nc->last_io_time = (time_t)mg_time();
#if !defined(NO_LIBC) && MG_ENABLE_HEXDUMP
        if (nc->mgr && nc->mgr->hexdump_file != NULL) {
            mg_hexdump_connection(nc, nc->mgr->hexdump_file, buf, n, MG_EV_RECV);
        }
#endif
        if (n != 0) {
            mg_call(nc, NULL, nc->user_data, MG_EV_RECV, &n);
        }
    }

out:
    mbuf_free(&lc->recv_mbuf);
    return n;
}

void mg_if_can_send_cb(struct mg_connection *nc) {
    int n = 0;
    const char *buf = nc->send_mbuf.buf;
    size_t len = nc->send_mbuf.len;

    if (nc->flags & (MG_F_CLOSE_IMMEDIATELY | MG_F_CONNECTING)) {
        return;
    }
    if (!(nc->flags & MG_F_UDP)) {
        if (nc->flags & MG_F_LISTENING) return;
        if (len > MG_TCP_IO_SIZE) len = MG_TCP_IO_SIZE;
    }
#if MG_ENABLE_SSL
    if (nc->flags & MG_F_SSL) {
        if (nc->flags & MG_F_SSL_HANDSHAKE_DONE) {
            if (len > 0) {
                n = mg_ssl_if_write(nc, buf, len);
                DBG(("%p -> %d bytes (SSL)", nc, n));
            }
            if (n < 0) {
                if (n == MG_SSL_WANT_WRITE) {
                    nc->flags |= MG_F_WANT_WRITE;
                    n = 0;
                }
                else {
                    nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                }
            }
            else {
                nc->flags &= ~MG_F_WANT_WRITE;
            }
        }
        else {
            mg_ssl_handshake(nc);
        }
    }
    else
#endif
        if (len > 0) {
            if (nc->flags & MG_F_UDP) {
                n = nc->iface->vtable->udp_send(nc, buf, len);
            }
            else {
                n = nc->iface->vtable->tcp_send(nc, buf, len);
            }
            DBG(("%p -> %d bytes", nc, n));
        }

#if !defined(NO_LIBC) && MG_ENABLE_HEXDUMP
    if (n > 0 && nc->mgr && nc->mgr->hexdump_file != NULL) {
        mg_hexdump_connection(nc, nc->mgr->hexdump_file, buf, n, MG_EV_SEND);
    }
#endif
    if (n < 0) {
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
    }
    else if (n > 0) {
        nc->last_io_time = (time_t)mg_time();
        mbuf_remove(&nc->send_mbuf, n);
        mbuf_trim(&nc->send_mbuf);
    }
    if (n != 0) mg_call(nc, NULL, nc->user_data, MG_EV_SEND, &n);
}

/*
 * Schedules an async connect for a resolved address and proto.
 * Called from two places: `mg_connect_opt()` and from async resolver.
 * When called from the async resolver, it must trigger `MG_EV_CONNECT` event
 * with a failure flag to indicate connection failure.
 */
MG_INTERNAL struct mg_connection *mg_do_connect(struct mg_connection *nc,
    int proto,
    union socket_address *sa) {
    LOG(LL_DEBUG, ("%p %s://%s:%hu", nc, proto == SOCK_DGRAM ? "udp" : "tcp",
        inet_ntoa(sa->sin.sin_addr), ntohs(sa->sin.sin_port)));

    nc->flags |= MG_F_CONNECTING;
    if (proto == SOCK_DGRAM) {
        nc->iface->vtable->connect_udp(nc);
    }
    else {
        nc->iface->vtable->connect_tcp(nc, sa);
    }
    mg_add_conn(nc->mgr, nc);
    return nc;
}

void mg_if_connect_cb(struct mg_connection *nc, int err) {
    LOG(LL_DEBUG,
        ("%p %s://%s:%hu -> %d", nc, (nc->flags & MG_F_UDP ? "udp" : "tcp"),
            inet_ntoa(nc->sa.sin.sin_addr), ntohs(nc->sa.sin.sin_port), err));
    nc->flags &= ~MG_F_CONNECTING;
    if (err != 0) {
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
    }
#if MG_ENABLE_SSL
    if (err == 0 && (nc->flags & MG_F_SSL)) {
        mg_ssl_handshake(nc);
    }
    else
#endif
    {
        mg_call(nc, NULL, nc->user_data, MG_EV_CONNECT, &err);
    }
}

#if MG_ENABLE_ASYNC_RESOLVER
/*
 * Callback for the async resolver on mg_connect_opt() call.
 * Main task of this function is to trigger MG_EV_CONNECT event with
 *    either failure (and dealloc the connection)
 *    or success (and proceed with connect()
 */
static void resolve_cb(struct mg_dns_message *msg, void *data,
    enum mg_resolve_err e) {
    struct mg_connection *nc = (struct mg_connection *) data;
    int i;
    int failure = -1;

    nc->flags &= ~MG_F_RESOLVING;
    if (msg != NULL) {
        /*
         * Take the first DNS A answer and run...
         */
        for (i = 0; i < msg->num_answers; i++) {
            if (msg->answers[i].rtype == MG_DNS_A_RECORD) {
                /*
                 * Async resolver guarantees that there is at least one answer.
                 * TODO(lsm): handle IPv6 answers too
                 */
                mg_dns_parse_record_data(msg, &msg->answers[i], &nc->sa.sin.sin_addr,
                    4);
                mg_do_connect(nc, nc->flags & MG_F_UDP ? SOCK_DGRAM : SOCK_STREAM,
                    &nc->sa);
                return;
            }
        }
    }

    if (e == MG_RESOLVE_TIMEOUT) {
        double now = mg_time();
        mg_call(nc, NULL, nc->user_data, MG_EV_TIMER, &now);
    }

    /*
     * If we get there was no MG_DNS_A_RECORD in the answer
     */
    mg_call(nc, NULL, nc->user_data, MG_EV_CONNECT, &failure);
    mg_call(nc, NULL, nc->user_data, MG_EV_CLOSE, NULL);
    mg_destroy_conn(nc, 1 /* destroy_if */);
}
#endif

struct mg_connection *mg_connect(struct mg_mgr *mgr, const char *address,
    MG_CB(mg_event_handler_t callback,
        void *user_data)) {
    struct mg_connect_opts opts;
    memset(&opts, 0, sizeof(opts));
    return mg_connect_opt(mgr, address, MG_CB(callback, user_data), opts);
}

void mg_ev_handler_empty(struct mg_connection *c, int ev,
    void *ev_data MG_UD_ARG(void *user_data)) {
    (void)c;
    (void)ev;
    (void)ev_data;
#if MG_ENABLE_CALLBACK_USERDATA
    (void) user_data;
#endif
}

struct mg_connection *mg_connect_opt(struct mg_mgr *mgr, const char *address,
    MG_CB(mg_event_handler_t callback,
        void *user_data),
    struct mg_connect_opts opts) {
    struct mg_connection *nc = NULL;
    int proto, rc;
    struct mg_add_sock_opts add_sock_opts;
    char host[MG_MAX_HOST_LEN];

    MG_COPY_COMMON_CONNECTION_OPTIONS(&add_sock_opts, &opts);

    if (callback == NULL) callback = mg_ev_handler_empty;

    if ((nc = mg_create_connection(mgr, callback, add_sock_opts)) == NULL) {
        return NULL;
    }

    if ((rc = mg_parse_address(address, &nc->sa, &proto, host, sizeof(host))) <
        0) {
        /* Address is malformed */
        MG_SET_PTRPTR(opts.error_string, "cannot parse address");
        mg_destroy_conn(nc, 1 /* destroy_if */);
        return NULL;
    }

    nc->flags |= opts.flags & _MG_ALLOWED_CONNECT_FLAGS_MASK;
    nc->flags |= (proto == SOCK_DGRAM) ? MG_F_UDP : 0;
#if MG_ENABLE_CALLBACK_USERDATA
    nc->user_data = user_data;
#else
    nc->user_data = opts.user_data;
#endif

#if MG_ENABLE_SSL
    LOG(LL_DEBUG,
        ("%p %s %s,%s,%s", nc, address, (opts.ssl_cert ? opts.ssl_cert : "-"),
        (opts.ssl_key ? opts.ssl_key : "-"),
            (opts.ssl_ca_cert ? opts.ssl_ca_cert : "-")));

    if (opts.ssl_cert != NULL || opts.ssl_ca_cert != NULL ||
        opts.ssl_psk_identity != NULL) {
        const char *err_msg = NULL;
        struct mg_ssl_if_conn_params params;
        if (nc->flags & MG_F_UDP) {
            MG_SET_PTRPTR(opts.error_string, "SSL for UDP is not supported");
            mg_destroy_conn(nc, 1 /* destroy_if */);
            return NULL;
        }
        memset(&params, 0, sizeof(params));
        params.cert = opts.ssl_cert;
        params.key = opts.ssl_key;
        params.ca_cert = opts.ssl_ca_cert;
        params.cipher_suites = opts.ssl_cipher_suites;
        params.psk_identity = opts.ssl_psk_identity;
        params.psk_key = opts.ssl_psk_key;
        if (opts.ssl_ca_cert != NULL) {
            if (opts.ssl_server_name != NULL) {
                if (strcmp(opts.ssl_server_name, "*") != 0) {
                    params.server_name = opts.ssl_server_name;
                }
            }
            else if (rc == 0) { /* If it's a DNS name, use host. */
                params.server_name = host;
            }
        }
        if (mg_ssl_if_conn_init(nc, &params, &err_msg) != MG_SSL_OK) {
            MG_SET_PTRPTR(opts.error_string, err_msg);
            mg_destroy_conn(nc, 1 /* destroy_if */);
            return NULL;
        }
        nc->flags |= MG_F_SSL;
    }
#endif /* MG_ENABLE_SSL */

    if (rc == 0) {
#if MG_ENABLE_ASYNC_RESOLVER
        /*
         * DNS resolution is required for host.
         * mg_parse_address() fills port in nc->sa, which we pass to resolve_cb()
         */
        struct mg_connection *dns_conn = NULL;
        struct mg_resolve_async_opts o;
        memset(&o, 0, sizeof(o));
        o.dns_conn = &dns_conn;
        o.nameserver = opts.nameserver;
        if (mg_resolve_async_opt(nc->mgr, host, MG_DNS_A_RECORD, resolve_cb, nc,
            o) != 0) {
            MG_SET_PTRPTR(opts.error_string, "cannot schedule DNS lookup");
            mg_destroy_conn(nc, 1 /* destroy_if */);
            return NULL;
        }
        nc->priv_2 = dns_conn;
        nc->flags |= MG_F_RESOLVING;
        return nc;
#else
        MG_SET_PTRPTR(opts.error_string, "Resolver is disabled");
        mg_destroy_conn(nc, 1 /* destroy_if */);
        return NULL;
#endif
    }
    else {
        /* Address is parsed and resolved to IP. proceed with connect() */
        return mg_do_connect(nc, proto, &nc->sa);
    }
}

struct mg_connection *mg_bind(struct mg_mgr *srv, const char *address,
    MG_CB(mg_event_handler_t event_handler,
        void *user_data)) {
    struct mg_bind_opts opts;
    memset(&opts, 0, sizeof(opts));
    return mg_bind_opt(srv, address, MG_CB(event_handler, user_data), opts);
}

struct mg_connection *mg_bind_opt(struct mg_mgr *mgr, const char *address,
    MG_CB(mg_event_handler_t callback,
        void *user_data),
    struct mg_bind_opts opts) {
    union socket_address sa;
    struct mg_connection *nc = NULL;
    int proto, rc;
    struct mg_add_sock_opts add_sock_opts;
    char host[MG_MAX_HOST_LEN];

#if MG_ENABLE_CALLBACK_USERDATA
    opts.user_data = user_data;
#endif

    if (callback == NULL) callback = mg_ev_handler_empty;

    MG_COPY_COMMON_CONNECTION_OPTIONS(&add_sock_opts, &opts);

    if (mg_parse_address(address, &sa, &proto, host, sizeof(host)) <= 0) {
        MG_SET_PTRPTR(opts.error_string, "cannot parse address");
        return NULL;
    }

    nc = mg_create_connection(mgr, callback, add_sock_opts);
    if (nc == NULL) {
        return NULL;
    }

    nc->sa = sa;
    nc->flags |= MG_F_LISTENING;
    if (proto == SOCK_DGRAM) nc->flags |= MG_F_UDP;

#if MG_ENABLE_SSL
    DBG(("%p %s %s,%s,%s", nc, address, (opts.ssl_cert ? opts.ssl_cert : "-"),
        (opts.ssl_key ? opts.ssl_key : "-"),
        (opts.ssl_ca_cert ? opts.ssl_ca_cert : "-")));

    if (opts.ssl_cert != NULL || opts.ssl_ca_cert != NULL) {
        const char *err_msg = NULL;
        struct mg_ssl_if_conn_params params;
        if (nc->flags & MG_F_UDP) {
            MG_SET_PTRPTR(opts.error_string, "SSL for UDP is not supported");
            mg_destroy_conn(nc, 1 /* destroy_if */);
            return NULL;
        }
        memset(&params, 0, sizeof(params));
        params.cert = opts.ssl_cert;
        params.key = opts.ssl_key;
        params.ca_cert = opts.ssl_ca_cert;
        params.cipher_suites = opts.ssl_cipher_suites;
        if (mg_ssl_if_conn_init(nc, &params, &err_msg) != MG_SSL_OK) {
            MG_SET_PTRPTR(opts.error_string, err_msg);
            mg_destroy_conn(nc, 1 /* destroy_if */);
            return NULL;
        }
        nc->flags |= MG_F_SSL;
    }
#endif /* MG_ENABLE_SSL */

    if (nc->flags & MG_F_UDP) {
        rc = nc->iface->vtable->listen_udp(nc, &nc->sa);
    }
    else {
        rc = nc->iface->vtable->listen_tcp(nc, &nc->sa);
    }
    if (rc != 0) {
        DBG(("Failed to open listener: %d", rc));
        MG_SET_PTRPTR(opts.error_string, "failed to open listener");
        mg_destroy_conn(nc, 1 /* destroy_if */);
        return NULL;
    }
    mg_add_conn(nc->mgr, nc);

    return nc;
}

struct mg_connection *mg_next(struct mg_mgr *s, struct mg_connection *conn) {
    return conn == NULL ? s->active_connections : conn->next;
}

#if MG_ENABLE_BROADCAST
void mg_broadcast(struct mg_mgr *mgr, mg_event_handler_t cb, void *data,
    size_t len) {
    struct ctl_msg ctl_msg;

    /*
     * Mongoose manager has a socketpair, `struct mg_mgr::ctl`,
     * where `mg_broadcast()` pushes the message.
     * `mg_mgr_poll()` wakes up, reads a message from the socket pair, and calls
     * specified callback for each connection. Thus the callback function executes
     * in event manager thread.
     */
    if (mgr->ctl[0] != INVALID_SOCKET && data != NULL &&
        len < sizeof(ctl_msg.message)) {
        size_t dummy;

        ctl_msg.callback = cb;
        memcpy(ctl_msg.message, data, len);
        dummy = MG_SEND_FUNC(mgr->ctl[0], (char *)&ctl_msg,
            offsetof(struct ctl_msg, message) + len, 0);
        dummy = MG_RECV_FUNC(mgr->ctl[0], (char *)&len, 1, 0);
        (void)dummy; /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25509 */
    }
}
#endif /* MG_ENABLE_BROADCAST */

static int isbyte(int n) {
    return n >= 0 && n <= 255;
}

static int parse_net(const char *spec, uint32_t *net, uint32_t *mask) {
    int n, a, b, c, d, slash = 32, len = 0;

    if ((sscanf(spec, "%d.%d.%d.%d/%d%n", &a, &b, &c, &d, &slash, &n) == 5 ||
        sscanf(spec, "%d.%d.%d.%d%n", &a, &b, &c, &d, &n) == 4) &&
        isbyte(a) && isbyte(b) && isbyte(c) && isbyte(d) && slash >= 0 &&
        slash < 33) {
        len = n;
        *net =
            ((uint32_t)a << 24) | ((uint32_t)b << 16) | ((uint32_t)c << 8) | d;
        *mask = slash ? 0xffffffffU << (32 - slash) : 0;
    }

    return len;
}

int mg_check_ip_acl(const char *acl, uint32_t remote_ip) {
    int allowed, flag;
    uint32_t net, mask;
    struct mg_str vec;

    /* If any ACL is set, deny by default */
    allowed = (acl == NULL || *acl == '\0') ? '+' : '-';

    while ((acl = mg_next_comma_list_entry(acl, &vec, NULL)) != NULL) {
        flag = vec.p[0];
        if ((flag != '+' && flag != '-') ||
            parse_net(&vec.p[1], &net, &mask) == 0) {
            return -1;
        }

        if (net == (remote_ip & mask)) {
            allowed = flag;
        }
    }

    DBG(("%08x %c", (unsigned int)remote_ip, allowed));
    return allowed == '+';
}

/* Move data from one connection to another */
void mg_forward(struct mg_connection *from, struct mg_connection *to) {
    mg_send(to, from->recv_mbuf.buf, from->recv_mbuf.len);
    mbuf_remove(&from->recv_mbuf, from->recv_mbuf.len);
}

double mg_set_timer(struct mg_connection *c, double timestamp) {
    double result = c->ev_timer_time;
    c->ev_timer_time = timestamp;
    /*
     * If this connection is resolving, it's not in the list of active
     * connections, so not processed yet. It has a DNS resolver connection
     * linked to it. Set up a timer for the DNS connection.
     */
    DBG(("%p %p %d -> %lu", c, c->priv_2, (c->flags & MG_F_RESOLVING ? 1 : 0),
        (unsigned long)timestamp));
    if ((c->flags & MG_F_RESOLVING) && c->priv_2 != NULL) {
        mg_set_timer((struct mg_connection *) c->priv_2, timestamp);
    }
    return result;
}

void mg_sock_set(struct mg_connection *nc, sock_t sock) {
    if (sock != INVALID_SOCKET) {
        nc->iface->vtable->sock_set(nc, sock);
    }
}

void mg_if_get_conn_addr(struct mg_connection *nc, int remote,
    union socket_address *sa) {
    nc->iface->vtable->get_conn_addr(nc, remote, sa);
}

struct mg_connection *mg_add_sock_opt(struct mg_mgr *s, sock_t sock,
    MG_CB(mg_event_handler_t callback,
        void *user_data),
    struct mg_add_sock_opts opts) {
#if MG_ENABLE_CALLBACK_USERDATA
    opts.user_data = user_data;
#endif

    struct mg_connection *nc = mg_create_connection_base(s, callback, opts);
    if (nc != NULL) {
        mg_sock_set(nc, sock);
        mg_add_conn(nc->mgr, nc);
    }
    return nc;
}

struct mg_connection *mg_add_sock(struct mg_mgr *s, sock_t sock,
    MG_CB(mg_event_handler_t callback,
        void *user_data)) {
    struct mg_add_sock_opts opts;
    memset(&opts, 0, sizeof(opts));
    return mg_add_sock_opt(s, sock, MG_CB(callback, user_data), opts);
}

double mg_time(void) {
    return cs_time();
}
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_net_if_socket.h"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

#ifndef CS_MONGOOSE_SRC_NET_IF_SOCKET_H_
#define CS_MONGOOSE_SRC_NET_IF_SOCKET_H_

 /* Amalgamated: #include "mg_net_if.h" */

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#ifndef MG_ENABLE_NET_IF_SOCKET
#define MG_ENABLE_NET_IF_SOCKET MG_NET_IF == MG_NET_IF_SOCKET
#endif

    extern const struct mg_iface_vtable mg_socket_iface_vtable;

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* CS_MONGOOSE_SRC_NET_IF_SOCKET_H_ */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_net_if_socks.h"
#endif
/*
* Copyright (c) 2014-2017 Cesanta Software Limited
* All rights reserved
*/

#ifndef CS_MONGOOSE_SRC_NET_IF_SOCKS_H_
#define CS_MONGOOSE_SRC_NET_IF_SOCKS_H_

#if MG_ENABLE_SOCKS
/* Amalgamated: #include "mg_net_if.h" */

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

    extern const struct mg_iface_vtable mg_socks_iface_vtable;

#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* MG_ENABLE_SOCKS */
#endif /* CS_MONGOOSE_SRC_NET_IF_SOCKS_H_ */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_net_if.c"
#endif
/* Amalgamated: #include "mg_net_if.h" */
/* Amalgamated: #include "mg_internal.h" */
/* Amalgamated: #include "mg_net_if_socket.h" */

extern const struct mg_iface_vtable mg_default_iface_vtable;

const struct mg_iface_vtable *mg_ifaces[] = {
    &mg_default_iface_vtable,
};

int mg_num_ifaces = (int)(sizeof(mg_ifaces) / sizeof(mg_ifaces[0]));

struct mg_iface *mg_if_create_iface(const struct mg_iface_vtable *vtable,
    struct mg_mgr *mgr) {
    struct mg_iface *iface = (struct mg_iface *) MG_CALLOC(1, sizeof(*iface));
    iface->mgr = mgr;
    iface->data = NULL;
    iface->vtable = vtable;
    return iface;
}

struct mg_iface *mg_find_iface(struct mg_mgr *mgr,
    const struct mg_iface_vtable *vtable,
    struct mg_iface *from) {
    int i = 0;
    if (from != NULL) {
        for (i = 0; i < mgr->num_ifaces; i++) {
            if (mgr->ifaces[i] == from) {
                i++;
                break;
            }
        }
    }

    for (; i < mgr->num_ifaces; i++) {
        if (mgr->ifaces[i]->vtable == vtable) {
            return mgr->ifaces[i];
        }
    }
    return NULL;
}

double mg_mgr_min_timer(const struct mg_mgr *mgr) {
    double min_timer = 0;
    struct mg_connection *nc;
    for (nc = mgr->active_connections; nc != NULL; nc = nc->next) {
        if (nc->ev_timer_time <= 0) continue;
        if (min_timer == 0 || nc->ev_timer_time < min_timer) {
            min_timer = nc->ev_timer_time;
        }
    }
    return min_timer;
}
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_net_if_null.c"
#endif
/*
 * Copyright (c) 2018 Cesanta Software Limited
 * All rights reserved
 *
 * This software is dual-licensed: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. For the terms of this
 * license, see <http://www.gnu.org/licenses/>.
 *
 * You are free to use this software under the terms of the GNU General
 * Public License, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * Alternatively, you can license this software under a commercial
 * license, as set out in <https://www.cesanta.com/license>.
 */

static void mg_null_if_connect_tcp(struct mg_connection *c,
    const union socket_address *sa) {
    c->flags |= MG_F_CLOSE_IMMEDIATELY;
    (void)sa;
}

static void mg_null_if_connect_udp(struct mg_connection *c) {
    c->flags |= MG_F_CLOSE_IMMEDIATELY;
}

static int mg_null_if_listen_tcp(struct mg_connection *c,
    union socket_address *sa) {
    (void)c;
    (void)sa;
    return -1;
}

static int mg_null_if_listen_udp(struct mg_connection *c,
    union socket_address *sa) {
    (void)c;
    (void)sa;
    return -1;
}

static int mg_null_if_tcp_send(struct mg_connection *c, const void *buf,
    size_t len) {
    (void)c;
    (void)buf;
    (void)len;
    return -1;
}

static int mg_null_if_udp_send(struct mg_connection *c, const void *buf,
    size_t len) {
    (void)c;
    (void)buf;
    (void)len;
    return -1;
}

int mg_null_if_tcp_recv(struct mg_connection *c, void *buf, size_t len) {
    (void)c;
    (void)buf;
    (void)len;
    return -1;
}

int mg_null_if_udp_recv(struct mg_connection *c, void *buf, size_t len,
    union socket_address *sa, size_t *sa_len) {
    (void)c;
    (void)buf;
    (void)len;
    (void)sa;
    (void)sa_len;
    return -1;
}

static int mg_null_if_create_conn(struct mg_connection *c) {
    (void)c;
    return 1;
}

static void mg_null_if_destroy_conn(struct mg_connection *c) {
    (void)c;
}

static void mg_null_if_sock_set(struct mg_connection *c, sock_t sock) {
    (void)c;
    (void)sock;
}

static void mg_null_if_init(struct mg_iface *iface) {
    (void)iface;
}

static void mg_null_if_free(struct mg_iface *iface) {
    (void)iface;
}

static void mg_null_if_add_conn(struct mg_connection *c) {
    c->sock = INVALID_SOCKET;
    c->flags |= MG_F_CLOSE_IMMEDIATELY;
}

static void mg_null_if_remove_conn(struct mg_connection *c) {
    (void)c;
}

static time_t mg_null_if_poll(struct mg_iface *iface, int timeout_ms) {
    struct mg_mgr *mgr = iface->mgr;
    struct mg_connection *nc, *tmp;
    double now = mg_time();
    /* We basically just run timers and poll. */
    for (nc = mgr->active_connections; nc != NULL; nc = tmp) {
        tmp = nc->next;
        mg_if_poll(nc, now);
    }
    (void)timeout_ms;
    return (time_t)now;
}

static void mg_null_if_get_conn_addr(struct mg_connection *c, int remote,
    union socket_address *sa) {
    (void)c;
    (void)remote;
    (void)sa;
}

#define MG_NULL_IFACE_VTABLE                                                   \
  {                                                                            \
    mg_null_if_init, mg_null_if_free, mg_null_if_add_conn,                     \
        mg_null_if_remove_conn, mg_null_if_poll, mg_null_if_listen_tcp,        \
        mg_null_if_listen_udp, mg_null_if_connect_tcp, mg_null_if_connect_udp, \
        mg_null_if_tcp_send, mg_null_if_udp_send, mg_null_if_tcp_recv,         \
        mg_null_if_udp_recv, mg_null_if_create_conn, mg_null_if_destroy_conn,  \
        mg_null_if_sock_set, mg_null_if_get_conn_addr,                         \
  }

const struct mg_iface_vtable mg_null_iface_vtable = MG_NULL_IFACE_VTABLE;

#if MG_NET_IF == MG_NET_IF_NULL
const struct mg_iface_vtable mg_default_iface_vtable = MG_NULL_IFACE_VTABLE;
#endif /* MG_NET_IF == MG_NET_IF_NULL */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_net_if_socket.c"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_NET_IF_SOCKET

 /* Amalgamated: #include "mg_net_if_socket.h" */
 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "mg_util.h" */

static sock_t mg_open_listening_socket(union socket_address *sa, int type,
    int proto);

void mg_set_non_blocking_mode(sock_t sock) {
#ifdef _WIN32
    unsigned long on = 1;
    ioctlsocket(sock, FIONBIO, &on);
#else
    int flags = fcntl(sock, F_GETFL, 0);
    fcntl(sock, F_SETFL, flags | O_NONBLOCK);
#endif
}

static int mg_is_error(void) {
    int err = mg_get_errno();
    return err != EINPROGRESS && err != EWOULDBLOCK
#ifndef WINCE
        && err != EAGAIN && err != EINTR
#endif
#ifdef _WIN32
        && WSAGetLastError() != WSAEINTR && WSAGetLastError() != WSAEWOULDBLOCK
#endif
        ;
}

void mg_socket_if_connect_tcp(struct mg_connection *nc,
    const union socket_address *sa) {
    int rc, proto = 0;
    nc->sock = socket(AF_INET, SOCK_STREAM, proto);
    if (nc->sock == INVALID_SOCKET) {
        nc->err = mg_get_errno() ? mg_get_errno() : 1;
        return;
    }
#if !defined(MG_ESP8266)
    mg_set_non_blocking_mode(nc->sock);
#endif
    rc = connect(nc->sock, &sa->sa, sizeof(sa->sin));
    nc->err = rc < 0 && mg_is_error() ? mg_get_errno() : 0;
    DBG(("%p sock %d rc %d errno %d err %d", nc, nc->sock, rc, mg_get_errno(),
        nc->err));
}

void mg_socket_if_connect_udp(struct mg_connection *nc) {
    nc->sock = socket(AF_INET, SOCK_DGRAM, 0);
    if (nc->sock == INVALID_SOCKET) {
        nc->err = mg_get_errno() ? mg_get_errno() : 1;
        return;
    }
    if (nc->flags & MG_F_ENABLE_BROADCAST) {
        int optval = 1;
        if (setsockopt(nc->sock, SOL_SOCKET, SO_BROADCAST, (const char *)&optval,
            sizeof(optval)) < 0) {
            nc->err = mg_get_errno() ? mg_get_errno() : 1;
            return;
        }
    }
    nc->err = 0;
}

int mg_socket_if_listen_tcp(struct mg_connection *nc,
    union socket_address *sa) {
    int proto = 0;
    sock_t sock = mg_open_listening_socket(sa, SOCK_STREAM, proto);
    if (sock == INVALID_SOCKET) {
        return (mg_get_errno() ? mg_get_errno() : 1);
    }
    mg_sock_set(nc, sock);
    return 0;
}

static int mg_socket_if_listen_udp(struct mg_connection *nc,
    union socket_address *sa) {
    sock_t sock = mg_open_listening_socket(sa, SOCK_DGRAM, 0);
    if (sock == INVALID_SOCKET) return (mg_get_errno() ? mg_get_errno() : 1);
    mg_sock_set(nc, sock);
    return 0;
}

static int mg_socket_if_tcp_send(struct mg_connection *nc, const void *buf,
    size_t len) {
    int n = (int)MG_SEND_FUNC(nc->sock, buf, len, 0);
    if (n < 0 && !mg_is_error()) n = 0;
    return n;
}

static int mg_socket_if_udp_send(struct mg_connection *nc, const void *buf,
    size_t len) {
    int n = sendto(nc->sock, buf, len, 0, &nc->sa.sa, sizeof(nc->sa.sin));
    if (n < 0 && !mg_is_error()) n = 0;
    return n;
}

static int mg_socket_if_tcp_recv(struct mg_connection *nc, void *buf,
    size_t len) {
    int n = (int)MG_RECV_FUNC(nc->sock, buf, len, 0);
    if (n == 0) {
        /* Orderly shutdown of the socket, try flushing output. */
        nc->flags |= MG_F_SEND_AND_CLOSE;
    }
    else if (n < 0 && !mg_is_error()) {
        n = 0;
    }
    return n;
}

static int mg_socket_if_udp_recv(struct mg_connection *nc, void *buf,
    size_t len, union socket_address *sa,
    size_t *sa_len) {
    socklen_t sa_len_st = *sa_len;
    int n = recvfrom(nc->sock, buf, len, 0, &sa->sa, &sa_len_st);
    *sa_len = sa_len_st;
    if (n < 0 && !mg_is_error()) n = 0;
    return n;
}

int mg_socket_if_create_conn(struct mg_connection *nc) {
    (void)nc;
    return 1;
}

void mg_socket_if_destroy_conn(struct mg_connection *nc) {
    if (nc->sock == INVALID_SOCKET) return;
    if (!(nc->flags & MG_F_UDP)) {
        closesocket(nc->sock);
    }
    else {
        /* Only close outgoing UDP sockets or listeners. */
        if (nc->listener == NULL) closesocket(nc->sock);
    }
    nc->sock = INVALID_SOCKET;
}

static int mg_accept_conn(struct mg_connection *lc) {
    struct mg_connection *nc;
    union socket_address sa;
    socklen_t sa_len = sizeof(sa);
    /* NOTE(lsm): on Windows, sock is always > FD_SETSIZE */
    sock_t sock = accept(lc->sock, &sa.sa, &sa_len);
    if (sock == INVALID_SOCKET) {
        if (mg_is_error()) {
            DBG(("%p: failed to accept: %d", lc, mg_get_errno()));
        }
        return 0;
    }
    nc = mg_if_accept_new_conn(lc);
    if (nc == NULL) {
        closesocket(sock);
        return 0;
    }
    DBG(("%p conn from %s:%d", nc, inet_ntoa(sa.sin.sin_addr),
        ntohs(sa.sin.sin_port)));
    mg_sock_set(nc, sock);
    mg_if_accept_tcp_cb(nc, &sa, sa_len);
    return 1;
}

/* 'sa' must be an initialized address to bind to */
static sock_t mg_open_listening_socket(union socket_address *sa, int type,
    int proto) {
    socklen_t sa_len =
        (sa->sa.sa_family == AF_INET) ? sizeof(sa->sin) : sizeof(sa->sin6);
    sock_t sock = INVALID_SOCKET;
#if !MG_LWIP
    int on = 1;
#endif

    if ((sock = socket(sa->sa.sa_family, type, proto)) != INVALID_SOCKET &&
#if !MG_LWIP /* LWIP doesn't support either */
#if defined(_WIN32) && defined(SO_EXCLUSIVEADDRUSE) && !defined(WINCE)
        /* "Using SO_REUSEADDR and SO_EXCLUSIVEADDRUSE" http://goo.gl/RmrFTm */
        !setsockopt(sock, SOL_SOCKET, SO_EXCLUSIVEADDRUSE, (void *)&on,
            sizeof(on)) &&
#endif

#if !defined(_WIN32) || !defined(SO_EXCLUSIVEADDRUSE)
        /*
         * SO_RESUSEADDR is not enabled on Windows because the semantics of
         * SO_REUSEADDR on UNIX and Windows is different. On Windows,
         * SO_REUSEADDR allows to bind a socket to a port without error even if
         * the port is already open by another program. This is not the behavior
         * SO_REUSEADDR was designed for, and leads to hard-to-track failure
         * scenarios. Therefore, SO_REUSEADDR was disabled on Windows unless
         * SO_EXCLUSIVEADDRUSE is supported and set on a socket.
         */
        !setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)) &&
#endif
#endif /* !MG_LWIP */

        !bind(sock, &sa->sa, sa_len) &&
        (type == SOCK_DGRAM || listen(sock, SOMAXCONN) == 0)) {
#if !MG_LWIP
        mg_set_non_blocking_mode(sock);
        /* In case port was set to 0, get the real port number */
        (void)getsockname(sock, &sa->sa, &sa_len);
#endif
    }
    else if (sock != INVALID_SOCKET) {
        closesocket(sock);
        sock = INVALID_SOCKET;
    }

    return sock;
}

#define _MG_F_FD_CAN_READ 1
#define _MG_F_FD_CAN_WRITE 1 << 1
#define _MG_F_FD_ERROR 1 << 2

void mg_mgr_handle_conn(struct mg_connection *nc, int fd_flags, double now) {
    int worth_logging =
        fd_flags != 0 || (nc->flags & (MG_F_WANT_READ | MG_F_WANT_WRITE));
    if (worth_logging) {
        DBG(("%p fd=%d fd_flags=%d nc_flags=0x%lx rmbl=%d smbl=%d", nc, nc->sock,
            fd_flags, nc->flags, (int)nc->recv_mbuf.len,
            (int)nc->send_mbuf.len));
    }

    if (!mg_if_poll(nc, now)) return;

    if (nc->flags & MG_F_CONNECTING) {
        if (fd_flags != 0) {
            int err = 0;
#if !defined(MG_ESP8266)
            if (!(nc->flags & MG_F_UDP)) {
                socklen_t len = sizeof(err);
                int ret =
                    getsockopt(nc->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &len);
                if (ret != 0) {
                    err = 1;
                }
                else if (err == EAGAIN || err == EWOULDBLOCK) {
                    err = 0;
                }
            }
#else
            /*
             * On ESP8266 we use blocking connect.
             */
            err = nc->err;
#endif
            mg_if_connect_cb(nc, err);
        }
        else if (nc->err != 0) {
            mg_if_connect_cb(nc, nc->err);
        }
    }

    if (fd_flags & _MG_F_FD_CAN_READ) {
        if (nc->flags & MG_F_UDP) {
            mg_if_can_recv_cb(nc);
        }
        else {
            if (nc->flags & MG_F_LISTENING) {
                /*
                 * We're not looping here, and accepting just one connection at
                 * a time. The reason is that eCos does not respect non-blocking
                 * flag on a listening socket and hangs in a loop.
                 */
                mg_accept_conn(nc);
            }
            else {
                mg_if_can_recv_cb(nc);
            }
        }
    }

    if (fd_flags & _MG_F_FD_CAN_WRITE) mg_if_can_send_cb(nc);

    if (worth_logging) {
        DBG(("%p after fd=%d nc_flags=0x%lx rmbl=%d smbl=%d", nc, nc->sock,
            nc->flags, (int)nc->recv_mbuf.len, (int)nc->send_mbuf.len));
    }
}

#if MG_ENABLE_BROADCAST
static void mg_mgr_handle_ctl_sock(struct mg_mgr *mgr) {
    struct ctl_msg ctl_msg;
    int len =
        (int)MG_RECV_FUNC(mgr->ctl[1], (char *)&ctl_msg, sizeof(ctl_msg), 0);
    size_t dummy = MG_SEND_FUNC(mgr->ctl[1], ctl_msg.message, 1, 0);
    DBG(("read %d from ctl socket", len));
    (void)dummy; /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25509 */
    if (len >= (int) sizeof(ctl_msg.callback) && ctl_msg.callback != NULL) {
        struct mg_connection *nc;
        for (nc = mg_next(mgr, NULL); nc != NULL; nc = mg_next(mgr, nc)) {
            ctl_msg.callback(nc, MG_EV_POLL,
                ctl_msg.message MG_UD_ARG(nc->user_data));
        }
    }
}
#endif

/* Associate a socket to a connection. */
void mg_socket_if_sock_set(struct mg_connection *nc, sock_t sock) {
    mg_set_non_blocking_mode(sock);
    mg_set_close_on_exec(sock);
    nc->sock = sock;
    DBG(("%p %d", nc, sock));
}

void mg_socket_if_init(struct mg_iface *iface) {
    (void)iface;
    DBG(("%p using select()", iface->mgr));
#if MG_ENABLE_BROADCAST
    mg_socketpair(iface->mgr->ctl, SOCK_DGRAM);
#endif
}

void mg_socket_if_free(struct mg_iface *iface) {
    (void)iface;
}

void mg_socket_if_add_conn(struct mg_connection *nc) {
    (void)nc;
}

void mg_socket_if_remove_conn(struct mg_connection *nc) {
    (void)nc;
}

void mg_add_to_set(sock_t sock, fd_set *set, sock_t *max_fd) {
    if (sock != INVALID_SOCKET
#ifdef __unix__
        && sock < (sock_t)FD_SETSIZE
#endif
        ) {
        FD_SET(sock, set);
        if (*max_fd == INVALID_SOCKET || sock > *max_fd) {
            *max_fd = sock;
        }
    }
}

time_t mg_socket_if_poll(struct mg_iface *iface, int timeout_ms) {
    struct mg_mgr *mgr = iface->mgr;
    double now = mg_time();
    double min_timer;
    struct mg_connection *nc, *tmp;
    struct timeval tv;
    fd_set read_set, write_set, err_set;
    sock_t max_fd = INVALID_SOCKET;
    int num_fds, num_ev, num_timers = 0;
#ifdef __unix__
    int try_dup = 1;
#endif

    FD_ZERO(&read_set);
    FD_ZERO(&write_set);
    FD_ZERO(&err_set);
#if MG_ENABLE_BROADCAST
    mg_add_to_set(mgr->ctl[1], &read_set, &max_fd);
#endif

    /*
     * Note: it is ok to have connections with sock == INVALID_SOCKET in the list,
     * e.g. timer-only "connections".
     */
    min_timer = 0;
    for (nc = mgr->active_connections, num_fds = 0; nc != NULL; nc = tmp) {
        tmp = nc->next;

        if (nc->sock != INVALID_SOCKET) {
            num_fds++;

#ifdef __unix__
            /* A hack to make sure all our file descriptos fit into FD_SETSIZE. */
            if (nc->sock >= (sock_t)FD_SETSIZE && try_dup) {
                int new_sock = dup(nc->sock);
                if (new_sock >= 0) {
                    if (new_sock < (sock_t)FD_SETSIZE) {
                        closesocket(nc->sock);
                        DBG(("new sock %d -> %d", nc->sock, new_sock));
                        nc->sock = new_sock;
                    }
                    else {
                        closesocket(new_sock);
                        DBG(("new sock is still larger than FD_SETSIZE, disregard"));
                        try_dup = 0;
                    }
                }
                else {
                    try_dup = 0;
                }
            }
#endif

            if (nc->recv_mbuf.len < nc->recv_mbuf_limit &&
                (!(nc->flags & MG_F_UDP) || nc->listener == NULL)) {
                mg_add_to_set(nc->sock, &read_set, &max_fd);
            }

            if (((nc->flags & MG_F_CONNECTING) && !(nc->flags & MG_F_WANT_READ)) ||
                (nc->send_mbuf.len > 0 && !(nc->flags & MG_F_CONNECTING))) {
                mg_add_to_set(nc->sock, &write_set, &max_fd);
                mg_add_to_set(nc->sock, &err_set, &max_fd);
            }
        }

        if (nc->ev_timer_time > 0) {
            if (num_timers == 0 || nc->ev_timer_time < min_timer) {
                min_timer = nc->ev_timer_time;
            }
            num_timers++;
        }
    }

    /*
     * If there is a timer to be fired earlier than the requested timeout,
     * adjust the timeout.
     */
    if (num_timers > 0) {
        double timer_timeout_ms = (min_timer - mg_time()) * 1000 + 1 /* rounding */;
        if (timer_timeout_ms < timeout_ms) {
            timeout_ms = (int)timer_timeout_ms;
        }
    }
    if (timeout_ms < 0) timeout_ms = 0;

    tv.tv_sec = timeout_ms / 1000;
    tv.tv_usec = (timeout_ms % 1000) * 1000;

    num_ev = select((int)max_fd + 1, &read_set, &write_set, &err_set, &tv);
    now = mg_time();
#if 0
    DBG(("select @ %ld num_ev=%d of %d, timeout=%d", (long)now, num_ev, num_fds,
        timeout_ms));
#endif

#if MG_ENABLE_BROADCAST
    if (num_ev > 0 && mgr->ctl[1] != INVALID_SOCKET &&
        FD_ISSET(mgr->ctl[1], &read_set)) {
        mg_mgr_handle_ctl_sock(mgr);
    }
#endif

    for (nc = mgr->active_connections; nc != NULL; nc = tmp) {
        int fd_flags = 0;
        if (nc->sock != INVALID_SOCKET) {
            if (num_ev > 0) {
                fd_flags = (FD_ISSET(nc->sock, &read_set) &&
                    (!(nc->flags & MG_F_UDP) || nc->listener == NULL)
                    ? _MG_F_FD_CAN_READ
                    : 0) |
                    (FD_ISSET(nc->sock, &write_set) ? _MG_F_FD_CAN_WRITE : 0) |
                    (FD_ISSET(nc->sock, &err_set) ? _MG_F_FD_ERROR : 0);
            }
#if MG_LWIP
            /* With LWIP socket emulation layer, we don't get write events for UDP */
            if ((nc->flags & MG_F_UDP) && nc->listener == NULL) {
                fd_flags |= _MG_F_FD_CAN_WRITE;
            }
#endif
        }
        tmp = nc->next;
        mg_mgr_handle_conn(nc, fd_flags, now);
    }

    return (time_t)now;
}

#if MG_ENABLE_BROADCAST
MG_INTERNAL void mg_socketpair_close(sock_t *sock) {
    while (1) {
        if (closesocket(*sock) == -1 && errno == EINTR) continue;
        break;
    }
    *sock = INVALID_SOCKET;
}

MG_INTERNAL sock_t
mg_socketpair_accept(sock_t sock, union socket_address *sa, socklen_t sa_len) {
    sock_t rc;
    while (1) {
        if ((rc = accept(sock, &sa->sa, &sa_len)) == INVALID_SOCKET &&
            errno == EINTR)
            continue;
        break;
    }
    return rc;
}

int mg_socketpair(sock_t sp[2], int sock_type) {
    union socket_address sa, sa2;
    sock_t sock;
    socklen_t len = sizeof(sa.sin);
    int ret = 0;

    sock = sp[0] = sp[1] = INVALID_SOCKET;

    (void)memset(&sa, 0, sizeof(sa));
    sa.sin.sin_family = AF_INET;
    sa.sin.sin_addr.s_addr = htonl(0x7f000001); /* 127.0.0.1 */
    sa2 = sa;

    if ((sock = socket(AF_INET, sock_type, 0)) == INVALID_SOCKET) {
    }
    else if (bind(sock, &sa.sa, len) != 0) {
    }
    else if (sock_type == SOCK_STREAM && listen(sock, 1) != 0) {
    }
    else if (getsockname(sock, &sa.sa, &len) != 0) {
    }
    else if ((sp[0] = socket(AF_INET, sock_type, 0)) == INVALID_SOCKET) {
    }
    else if (sock_type == SOCK_STREAM && connect(sp[0], &sa.sa, len) != 0) {
    }
    else if (sock_type == SOCK_DGRAM &&
        (bind(sp[0], &sa2.sa, len) != 0 ||
            getsockname(sp[0], &sa2.sa, &len) != 0 ||
            connect(sp[0], &sa.sa, len) != 0 ||
            connect(sock, &sa2.sa, len) != 0)) {
    }
    else if ((sp[1] = (sock_type == SOCK_DGRAM ? sock : mg_socketpair_accept(
        sock, &sa, len))) ==
        INVALID_SOCKET) {
    }
    else {
        mg_set_close_on_exec(sp[0]);
        mg_set_close_on_exec(sp[1]);
        if (sock_type == SOCK_STREAM) mg_socketpair_close(&sock);
        ret = 1;
    }

    if (!ret) {
        if (sp[0] != INVALID_SOCKET) mg_socketpair_close(&sp[0]);
        if (sp[1] != INVALID_SOCKET) mg_socketpair_close(&sp[1]);
        if (sock != INVALID_SOCKET) mg_socketpair_close(&sock);
    }

    return ret;
}
#endif /* MG_ENABLE_BROADCAST */

static void mg_sock_get_addr(sock_t sock, int remote,
    union socket_address *sa) {
    socklen_t slen = sizeof(*sa);
    memset(sa, 0, slen);
    if (remote) {
        getpeername(sock, &sa->sa, &slen);
    }
    else {
        getsockname(sock, &sa->sa, &slen);
    }
}

void mg_sock_to_str(sock_t sock, char *buf, size_t len, int flags) {
    union socket_address sa;
    mg_sock_get_addr(sock, flags & MG_SOCK_STRINGIFY_REMOTE, &sa);
    mg_sock_addr_to_str(&sa, buf, len, flags);
}

void mg_socket_if_get_conn_addr(struct mg_connection *nc, int remote,
    union socket_address *sa) {
    if ((nc->flags & MG_F_UDP) && remote) {
        memcpy(sa, &nc->sa, sizeof(*sa));
        return;
    }
    mg_sock_get_addr(nc->sock, remote, sa);
}

/* clang-format off */
#define MG_SOCKET_IFACE_VTABLE                                          \
  {                                                                     \
    mg_socket_if_init,                                                  \
    mg_socket_if_free,                                                  \
    mg_socket_if_add_conn,                                              \
    mg_socket_if_remove_conn,                                           \
    mg_socket_if_poll,                                                  \
    mg_socket_if_listen_tcp,                                            \
    mg_socket_if_listen_udp,                                            \
    mg_socket_if_connect_tcp,                                           \
    mg_socket_if_connect_udp,                                           \
    mg_socket_if_tcp_send,                                              \
    mg_socket_if_udp_send,                                              \
    mg_socket_if_tcp_recv,                                              \
    mg_socket_if_udp_recv,                                              \
    mg_socket_if_create_conn,                                           \
    mg_socket_if_destroy_conn,                                          \
    mg_socket_if_sock_set,                                              \
    mg_socket_if_get_conn_addr,                                         \
  }
/* clang-format on */

const struct mg_iface_vtable mg_socket_iface_vtable = MG_SOCKET_IFACE_VTABLE;
#if MG_NET_IF == MG_NET_IF_SOCKET
const struct mg_iface_vtable mg_default_iface_vtable = MG_SOCKET_IFACE_VTABLE;
#endif

#endif /* MG_ENABLE_NET_IF_SOCKET */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_net_if_socks.c"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_SOCKS

struct socksdata {
    char *proxy_addr;        /* HOST:PORT of the socks5 proxy server */
    struct mg_connection *s; /* Respective connection to the server */
    struct mg_connection *c; /* Connection to the client */
};

static void socks_if_disband(struct socksdata *d) {
    LOG(LL_DEBUG, ("disbanding proxy %p %p", d->c, d->s));
    if (d->c) {
        d->c->flags |= MG_F_SEND_AND_CLOSE;
        d->c->user_data = NULL;
        d->c = NULL;
    }
    if (d->s) {
        d->s->flags |= MG_F_SEND_AND_CLOSE;
        d->s->user_data = NULL;
        d->s = NULL;
    }
}

static void socks_if_relay(struct mg_connection *s) {
    struct socksdata *d = (struct socksdata *) s->user_data;
    if (d == NULL || d->c == NULL || !(s->flags & MG_SOCKS_CONNECT_DONE) ||
        d->s == NULL) {
        return;
    }
    if (s->recv_mbuf.len > 0) mg_if_can_recv_cb(d->c);
    if (d->c->send_mbuf.len > 0 && s->send_mbuf.len == 0) mg_if_can_send_cb(d->c);
}

static void socks_if_handler(struct mg_connection *c, int ev, void *ev_data) {
    struct socksdata *d = (struct socksdata *) c->user_data;
    if (d == NULL) return;
    if (ev == MG_EV_CONNECT) {
        int res = *(int *)ev_data;
        if (res == 0) {
            /* Send handshake to the proxy server */
            unsigned char buf[] = { MG_SOCKS_VERSION, 1, MG_SOCKS_HANDSHAKE_NOAUTH };
            mg_send(d->s, buf, sizeof(buf));
            LOG(LL_DEBUG, ("Sent handshake to %s", d->proxy_addr));
        }
        else {
            LOG(LL_ERROR, ("Cannot connect to %s: %d", d->proxy_addr, res));
            d->c->flags |= MG_F_CLOSE_IMMEDIATELY;
        }
    }
    else if (ev == MG_EV_CLOSE) {
        socks_if_disband(d);
    }
    else if (ev == MG_EV_RECV) {
        /* Handle handshake reply */
        if (!(c->flags & MG_SOCKS_HANDSHAKE_DONE)) {
            /* TODO(lsm): process IPv6 too */
            unsigned char buf[10] = { MG_SOCKS_VERSION, MG_SOCKS_CMD_CONNECT, 0,
                                     MG_SOCKS_ADDR_IPV4 };
            if (c->recv_mbuf.len < 2) return;
            if ((unsigned char)c->recv_mbuf.buf[1] == MG_SOCKS_HANDSHAKE_FAILURE) {
                LOG(LL_ERROR, ("Server kicked us out"));
                socks_if_disband(d);
                return;
            }
            mbuf_remove(&c->recv_mbuf, 2);
            c->flags |= MG_SOCKS_HANDSHAKE_DONE;

            /* Send connect request */
            memcpy(buf + 4, &d->c->sa.sin.sin_addr, 4);
            memcpy(buf + 8, &d->c->sa.sin.sin_port, 2);
            mg_send(c, buf, sizeof(buf));
            LOG(LL_DEBUG, ("%p Sent connect request", c));
        }
        /* Process connect request */
        if ((c->flags & MG_SOCKS_HANDSHAKE_DONE) &&
            !(c->flags & MG_SOCKS_CONNECT_DONE)) {
            if (c->recv_mbuf.len < 10) return;
            if (c->recv_mbuf.buf[1] != MG_SOCKS_SUCCESS) {
                LOG(LL_ERROR, ("Socks connection error: %d", c->recv_mbuf.buf[1]));
                socks_if_disband(d);
                return;
            }
            mbuf_remove(&c->recv_mbuf, 10);
            c->flags |= MG_SOCKS_CONNECT_DONE;
            LOG(LL_DEBUG, ("%p Connect done %p", c, d->c));
            mg_if_connect_cb(d->c, 0);
        }
        socks_if_relay(c);
    }
    else if (ev == MG_EV_SEND || ev == MG_EV_POLL) {
        socks_if_relay(c);
    }
}

static void mg_socks_if_connect_tcp(struct mg_connection *c,
    const union socket_address *sa) {
    struct socksdata *d = (struct socksdata *) c->iface->data;
    d->c = c;
    d->s = mg_connect(c->mgr, d->proxy_addr, socks_if_handler);
    d->s->user_data = d;
    LOG(LL_DEBUG, ("%p %s %p %p", c, d->proxy_addr, d, d->s));
    (void)sa;
}

static void mg_socks_if_connect_udp(struct mg_connection *c) {
    (void)c;
}

static int mg_socks_if_listen_tcp(struct mg_connection *c,
    union socket_address *sa) {
    (void)c;
    (void)sa;
    return 0;
}

static int mg_socks_if_listen_udp(struct mg_connection *c,
    union socket_address *sa) {
    (void)c;
    (void)sa;
    return -1;
}

static int mg_socks_if_tcp_send(struct mg_connection *c, const void *buf,
    size_t len) {
    int res;
    struct socksdata *d = (struct socksdata *) c->iface->data;
    if (d->s == NULL) return -1;
    res = (int)mbuf_append(&d->s->send_mbuf, buf, len);
    DBG(("%p -> %d -> %p", c, res, d->s));
    return res;
}

static int mg_socks_if_udp_send(struct mg_connection *c, const void *buf,
    size_t len) {
    (void)c;
    (void)buf;
    (void)len;
    return -1;
}

int mg_socks_if_tcp_recv(struct mg_connection *c, void *buf, size_t len) {
    struct socksdata *d = (struct socksdata *) c->iface->data;
    if (d->s == NULL) return -1;
    if (len > d->s->recv_mbuf.len) len = d->s->recv_mbuf.len;
    if (len > 0) {
        memcpy(buf, d->s->recv_mbuf.buf, len);
        mbuf_remove(&d->s->recv_mbuf, len);
    }
    DBG(("%p <- %d <- %p", c, (int)len, d->s));
    return len;
}

int mg_socks_if_udp_recv(struct mg_connection *c, void *buf, size_t len,
    union socket_address *sa, size_t *sa_len) {
    (void)c;
    (void)buf;
    (void)len;
    (void)sa;
    (void)sa_len;
    return -1;
}

static int mg_socks_if_create_conn(struct mg_connection *c) {
    (void)c;
    return 1;
}

static void mg_socks_if_destroy_conn(struct mg_connection *c) {
    c->iface->vtable->free(c->iface);
    MG_FREE(c->iface);
    c->iface = NULL;
    LOG(LL_DEBUG, ("%p", c));
}

static void mg_socks_if_sock_set(struct mg_connection *c, sock_t sock) {
    (void)c;
    (void)sock;
}

static void mg_socks_if_init(struct mg_iface *iface) {
    (void)iface;
}

static void mg_socks_if_free(struct mg_iface *iface) {
    struct socksdata *d = (struct socksdata *) iface->data;
    LOG(LL_DEBUG, ("%p", iface));
    if (d != NULL) {
        socks_if_disband(d);
        MG_FREE(d->proxy_addr);
        MG_FREE(d);
        iface->data = NULL;
    }
}

static void mg_socks_if_add_conn(struct mg_connection *c) {
    c->sock = INVALID_SOCKET;
}

static void mg_socks_if_remove_conn(struct mg_connection *c) {
    (void)c;
}

static time_t mg_socks_if_poll(struct mg_iface *iface, int timeout_ms) {
    LOG(LL_DEBUG, ("%p", iface));
    (void)iface;
    (void)timeout_ms;
    return (time_t)cs_time();
}

static void mg_socks_if_get_conn_addr(struct mg_connection *c, int remote,
    union socket_address *sa) {
    LOG(LL_DEBUG, ("%p", c));
    (void)c;
    (void)remote;
    (void)sa;
}

const struct mg_iface_vtable mg_socks_iface_vtable = {
    mg_socks_if_init,          mg_socks_if_free,
    mg_socks_if_add_conn,      mg_socks_if_remove_conn,
    mg_socks_if_poll,          mg_socks_if_listen_tcp,
    mg_socks_if_listen_udp,    mg_socks_if_connect_tcp,
    mg_socks_if_connect_udp,   mg_socks_if_tcp_send,
    mg_socks_if_udp_send,      mg_socks_if_tcp_recv,
    mg_socks_if_udp_recv,      mg_socks_if_create_conn,
    mg_socks_if_destroy_conn,  mg_socks_if_sock_set,
    mg_socks_if_get_conn_addr,
};

struct mg_iface *mg_socks_mk_iface(struct mg_mgr *mgr, const char *proxy_addr) {
    struct mg_iface *iface = mg_if_create_iface(&mg_socks_iface_vtable, mgr);
    iface->data = MG_CALLOC(1, sizeof(struct socksdata));
    ((struct socksdata *) iface->data)->proxy_addr = strdup(proxy_addr);
    return iface;
}

#endif
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_ssl_if_openssl.c"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_SSL && MG_SSL_IF == MG_SSL_IF_OPENSSL

#ifdef __APPLE__
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#endif

#include <openssl/ssl.h>
#ifndef KR_VERSION
#include <openssl/tls1.h>
#endif

struct mg_ssl_if_ctx {
    SSL *ssl;
    SSL_CTX *ssl_ctx;
    struct mbuf psk;
    size_t identity_len;
};

void mg_ssl_if_init() {
    SSL_library_init();
}

enum mg_ssl_if_result mg_ssl_if_conn_accept(struct mg_connection *nc,
    struct mg_connection *lc) {
    struct mg_ssl_if_ctx *ctx =
        (struct mg_ssl_if_ctx *) MG_CALLOC(1, sizeof(*ctx));
    struct mg_ssl_if_ctx *lc_ctx = (struct mg_ssl_if_ctx *) lc->ssl_if_data;
    nc->ssl_if_data = ctx;
    if (ctx == NULL || lc_ctx == NULL) return MG_SSL_ERROR;
    ctx->ssl_ctx = lc_ctx->ssl_ctx;
    if ((ctx->ssl = SSL_new(ctx->ssl_ctx)) == NULL) {
        return MG_SSL_ERROR;
    }
    return MG_SSL_OK;
}

static enum mg_ssl_if_result mg_use_cert(SSL_CTX *ctx, const char *cert,
    const char *key, const char **err_msg);
static enum mg_ssl_if_result mg_use_ca_cert(SSL_CTX *ctx, const char *cert);
static enum mg_ssl_if_result mg_set_cipher_list(SSL_CTX *ctx, const char *cl);
static enum mg_ssl_if_result mg_ssl_if_ossl_set_psk(struct mg_ssl_if_ctx *ctx,
    const char *identity,
    const char *key_str);

enum mg_ssl_if_result mg_ssl_if_conn_init(
    struct mg_connection *nc, const struct mg_ssl_if_conn_params *params,
    const char **err_msg) {
    struct mg_ssl_if_ctx *ctx =
        (struct mg_ssl_if_ctx *) MG_CALLOC(1, sizeof(*ctx));
    DBG(("%p %s,%s,%s", nc, (params->cert ? params->cert : ""),
        (params->key ? params->key : ""),
        (params->ca_cert ? params->ca_cert : "")));
    if (ctx == NULL) {
        MG_SET_PTRPTR(err_msg, "Out of memory");
        return MG_SSL_ERROR;
    }
    nc->ssl_if_data = ctx;
    if (nc->flags & MG_F_LISTENING) {
        ctx->ssl_ctx = SSL_CTX_new(SSLv23_server_method());
    }
    else {
        ctx->ssl_ctx = SSL_CTX_new(SSLv23_client_method());
    }
    if (ctx->ssl_ctx == NULL) {
        MG_SET_PTRPTR(err_msg, "Failed to create SSL context");
        return MG_SSL_ERROR;
    }

#ifndef KR_VERSION
    /* Disable deprecated protocols. */
    SSL_CTX_set_options(ctx->ssl_ctx, SSL_OP_NO_SSLv2);
    SSL_CTX_set_options(ctx->ssl_ctx, SSL_OP_NO_SSLv3);
    SSL_CTX_set_options(ctx->ssl_ctx, SSL_OP_NO_TLSv1);
#ifdef MG_SSL_OPENSSL_NO_COMPRESSION
    SSL_CTX_set_options(ctx->ssl_ctx, SSL_OP_NO_COMPRESSION);
#endif
#ifdef MG_SSL_OPENSSL_CIPHER_SERVER_PREFERENCE
    SSL_CTX_set_options(ctx->ssl_ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
#endif
#else
    /* Krypton only supports TLSv1.2 anyway. */
#endif

    if (params->cert != NULL &&
        mg_use_cert(ctx->ssl_ctx, params->cert, params->key, err_msg) !=
        MG_SSL_OK) {
        return MG_SSL_ERROR;
    }

    if (params->ca_cert != NULL &&
        mg_use_ca_cert(ctx->ssl_ctx, params->ca_cert) != MG_SSL_OK) {
        MG_SET_PTRPTR(err_msg, "Invalid SSL CA cert");
        return MG_SSL_ERROR;
    }

    if (mg_set_cipher_list(ctx->ssl_ctx, params->cipher_suites) != MG_SSL_OK) {
        MG_SET_PTRPTR(err_msg, "Invalid cipher suite list");
        return MG_SSL_ERROR;
    }

    mbuf_init(&ctx->psk, 0);
    if (mg_ssl_if_ossl_set_psk(ctx, params->psk_identity, params->psk_key) !=
        MG_SSL_OK) {
        MG_SET_PTRPTR(err_msg, "Invalid PSK settings");
        return MG_SSL_ERROR;
    }

    if (!(nc->flags & MG_F_LISTENING) &&
        (ctx->ssl = SSL_new(ctx->ssl_ctx)) == NULL) {
        MG_SET_PTRPTR(err_msg, "Failed to create SSL session");
        return MG_SSL_ERROR;
    }

    if (params->server_name != NULL) {
#ifdef KR_VERSION
        SSL_CTX_kr_set_verify_name(ctx->ssl_ctx, params->server_name);
#else
        SSL_set_tlsext_host_name(ctx->ssl, params->server_name);
#endif
    }

    nc->flags |= MG_F_SSL;

    return MG_SSL_OK;
}

static enum mg_ssl_if_result mg_ssl_if_ssl_err(struct mg_connection *nc,
    int res) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    int err = SSL_get_error(ctx->ssl, res);
    if (err == SSL_ERROR_WANT_READ) return MG_SSL_WANT_READ;
    if (err == SSL_ERROR_WANT_WRITE) return MG_SSL_WANT_WRITE;
    DBG(("%p %p SSL error: %d %d", nc, ctx->ssl_ctx, res, err));
    nc->err = err;
    return MG_SSL_ERROR;
}

enum mg_ssl_if_result mg_ssl_if_handshake(struct mg_connection *nc) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    int server_side = (nc->listener != NULL);
    int res;
    /* If descriptor is not yet set, do it now. */
    if (SSL_get_fd(ctx->ssl) < 0) {
        if (SSL_set_fd(ctx->ssl, nc->sock) != 1) return MG_SSL_ERROR;
    }
    res = server_side ? SSL_accept(ctx->ssl) : SSL_connect(ctx->ssl);
    if (res != 1) return mg_ssl_if_ssl_err(nc, res);
    return MG_SSL_OK;
}

int mg_ssl_if_read(struct mg_connection *nc, void *buf, size_t buf_size) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    int n = SSL_read(ctx->ssl, buf, buf_size);
    DBG(("%p %d -> %d", nc, (int)buf_size, n));
    if (n < 0) return mg_ssl_if_ssl_err(nc, n);
    if (n == 0) nc->flags |= MG_F_CLOSE_IMMEDIATELY;
    return n;
}

int mg_ssl_if_write(struct mg_connection *nc, const void *data, size_t len) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    int n = SSL_write(ctx->ssl, data, len);
    DBG(("%p %d -> %d", nc, (int)len, n));
    if (n <= 0) return mg_ssl_if_ssl_err(nc, n);
    return n;
}

void mg_ssl_if_conn_close_notify(struct mg_connection *nc) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    if (ctx == NULL) return;
    SSL_shutdown(ctx->ssl);
}

void mg_ssl_if_conn_free(struct mg_connection *nc) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    if (ctx == NULL) return;
    nc->ssl_if_data = NULL;
    if (ctx->ssl != NULL) SSL_free(ctx->ssl);
    if (ctx->ssl_ctx != NULL && nc->listener == NULL) SSL_CTX_free(ctx->ssl_ctx);
    mbuf_free(&ctx->psk);
    memset(ctx, 0, sizeof(*ctx));
    MG_FREE(ctx);
}

/*
 * Cipher suite options used for TLS negotiation.
 * https://wiki.mozilla.org/Security/Server_Side_TLS#Recommended_configurations
 */
static const char mg_s_cipher_list[] =
#if defined(MG_SSL_CRYPTO_MODERN)
"ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:"
"ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:"
"DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:"
"ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:"
"ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:"
"ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:"
"DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:"
"DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:"
"!aNULL:!eNULL:!EXPORT:!DES:!RC4:!3DES:!MD5:!PSK"
#elif defined(MG_SSL_CRYPTO_OLD)
"ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:"
"ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:"
"DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:"
"ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:"
"ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:"
"ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:"
"DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:"
"DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:ECDHE-RSA-DES-CBC3-SHA:"
"ECDHE-ECDSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:"
"AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:DES-CBC3-SHA:"
"HIGH:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:"
"!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA"
#else /* Default - intermediate. */
"ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:"
"ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:"
"DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:"
"ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:"
"ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:"
"ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:"
"DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:"
"DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:"
"AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:"
"DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:"
"!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA"
#endif
;

/*
 * Default DH params for PFS cipher negotiation. This is a 2048-bit group.
 * Will be used if none are provided by the user in the certificate file.
 */
#if !MG_DISABLE_PFS && !defined(KR_VERSION)
static const char mg_s_default_dh_params[] =
"\
-----BEGIN DH PARAMETERS-----\n\
MIIBCAKCAQEAlvbgD/qh9znWIlGFcV0zdltD7rq8FeShIqIhkQ0C7hYFThrBvF2E\n\
Z9bmgaP+sfQwGpVlv9mtaWjvERbu6mEG7JTkgmVUJrUt/wiRzwTaCXBqZkdUO8Tq\n\
+E6VOEQAilstG90ikN1Tfo+K6+X68XkRUIlgawBTKuvKVwBhuvlqTGerOtnXWnrt\n\
ym//hd3cd5PBYGBix0i7oR4xdghvfR2WLVu0LgdThTBb6XP7gLd19cQ1JuBtAajZ\n\
wMuPn7qlUkEFDIkAZy59/Hue/H2Q2vU/JsvVhHWCQBL4F1ofEAt50il6ZxR1QfFK\n\
9VGKDC4oOgm9DlxwwBoC2FjqmvQlqVV3kwIBAg==\n\
-----END DH PARAMETERS-----\n";
#endif

static enum mg_ssl_if_result mg_use_ca_cert(SSL_CTX *ctx, const char *cert) {
    if (cert == NULL || strcmp(cert, "*") == 0) {
        return MG_SSL_OK;
    }
    SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, 0);
    return SSL_CTX_load_verify_locations(ctx, cert, NULL) == 1 ? MG_SSL_OK
        : MG_SSL_ERROR;
}

static enum mg_ssl_if_result mg_use_cert(SSL_CTX *ctx, const char *cert,
    const char *key,
    const char **err_msg) {
    if (key == NULL) key = cert;
    if (cert == NULL || cert[0] == '\0' || key == NULL || key[0] == '\0') {
        return MG_SSL_OK;
    }
    else if (SSL_CTX_use_certificate_file(ctx, cert, 1) == 0) {
        MG_SET_PTRPTR(err_msg, "Invalid SSL cert");
        return MG_SSL_ERROR;
    }
    else if (SSL_CTX_use_PrivateKey_file(ctx, key, 1) == 0) {
        MG_SET_PTRPTR(err_msg, "Invalid SSL key");
        return MG_SSL_ERROR;
    }
    else if (SSL_CTX_use_certificate_chain_file(ctx, cert) == 0) {
        MG_SET_PTRPTR(err_msg, "Invalid CA bundle");
        return MG_SSL_ERROR;
    }
    else {
        SSL_CTX_set_mode(ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
#if !MG_DISABLE_PFS && !defined(KR_VERSION)
        BIO *bio = NULL;
        DH *dh = NULL;

        /* Try to read DH parameters from the cert/key file. */
        bio = BIO_new_file(cert, "r");
        if (bio != NULL) {
            dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
            BIO_free(bio);
        }
        /*
         * If there are no DH params in the file, fall back to hard-coded ones.
         * Not ideal, but better than nothing.
         */
        if (dh == NULL) {
            bio = BIO_new_mem_buf((void *)mg_s_default_dh_params, -1);
            dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
            BIO_free(bio);
        }
        if (dh != NULL) {
            SSL_CTX_set_tmp_dh(ctx, dh);
            SSL_CTX_set_options(ctx, SSL_OP_SINGLE_DH_USE);
            DH_free(dh);
        }
#if OPENSSL_VERSION_NUMBER > 0x10002000L
        SSL_CTX_set_ecdh_auto(ctx, 1);
#endif
#endif
    }
    return MG_SSL_OK;
}

static enum mg_ssl_if_result mg_set_cipher_list(SSL_CTX *ctx, const char *cl) {
    return (SSL_CTX_set_cipher_list(ctx, cl ? cl : mg_s_cipher_list) == 1
        ? MG_SSL_OK
        : MG_SSL_ERROR);
}

#if !defined(KR_VERSION) && !defined(LIBRESSL_VERSION_NUMBER)
static unsigned int mg_ssl_if_ossl_psk_cb(SSL *ssl, const char *hint,
    char *identity,
    unsigned int max_identity_len,
    unsigned char *psk,
    unsigned int max_psk_len) {
    struct mg_ssl_if_ctx *ctx =
        (struct mg_ssl_if_ctx *) SSL_CTX_get_app_data(SSL_get_SSL_CTX(ssl));
    size_t key_len = ctx->psk.len - ctx->identity_len - 1;
    DBG(("hint: '%s'", (hint ? hint : "")));
    if (ctx->identity_len + 1 > max_identity_len) {
        DBG(("identity too long"));
        return 0;
    }
    if (key_len > max_psk_len) {
        DBG(("key too long"));
        return 0;
    }
    memcpy(identity, ctx->psk.buf, ctx->identity_len + 1);
    memcpy(psk, ctx->psk.buf + ctx->identity_len + 1, key_len);
    (void)ssl;
    return key_len;
}

static enum mg_ssl_if_result mg_ssl_if_ossl_set_psk(struct mg_ssl_if_ctx *ctx,
    const char *identity,
    const char *key_str) {
    unsigned char key[32];
    size_t key_len;
    size_t i = 0;
    if (identity == NULL && key_str == NULL) return MG_SSL_OK;
    if (identity == NULL || key_str == NULL) return MG_SSL_ERROR;
    key_len = strlen(key_str);
    if (key_len != 32 && key_len != 64) return MG_SSL_ERROR;
    memset(key, 0, sizeof(key));
    key_len = 0;
    for (i = 0; key_str[i] != '\0'; i++) {
        unsigned char c;
        char hc = tolower((int)key_str[i]);
        if (hc >= '0' && hc <= '9') {
            c = hc - '0';
        }
        else if (hc >= 'a' && hc <= 'f') {
            c = hc - 'a' + 0xa;
        }
        else {
            return MG_SSL_ERROR;
        }
        key_len = i / 2;
        key[key_len] <<= 4;
        key[key_len] |= c;
    }
    key_len++;
    DBG(("identity = '%s', key = (%u)", identity, (unsigned int)key_len));
    ctx->identity_len = strlen(identity);
    mbuf_append(&ctx->psk, identity, ctx->identity_len + 1);
    mbuf_append(&ctx->psk, key, key_len);
    SSL_CTX_set_psk_client_callback(ctx->ssl_ctx, mg_ssl_if_ossl_psk_cb);
    SSL_CTX_set_app_data(ctx->ssl_ctx, ctx);
    return MG_SSL_OK;
}
#else
static enum mg_ssl_if_result mg_ssl_if_ossl_set_psk(struct mg_ssl_if_ctx *ctx,
    const char *identity,
    const char *key_str) {
    (void)ctx;
    (void)identity;
    (void)key_str;
    /* Krypton / LibreSSL does not support PSK. */
    return MG_SSL_ERROR;
}
#endif /* !defined(KR_VERSION) && !defined(LIBRESSL_VERSION_NUMBER) */

const char *mg_set_ssl(struct mg_connection *nc, const char *cert,
    const char *ca_cert) {
    const char *err_msg = NULL;
    struct mg_ssl_if_conn_params params;
    memset(&params, 0, sizeof(params));
    params.cert = cert;
    params.ca_cert = ca_cert;
    if (mg_ssl_if_conn_init(nc, &params, &err_msg) != MG_SSL_OK) {
        return err_msg;
    }
    return NULL;
}

#endif /* MG_ENABLE_SSL && MG_SSL_IF == MG_SSL_IF_OPENSSL */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_ssl_if_mbedtls.c"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_SSL && MG_SSL_IF == MG_SSL_IF_MBEDTLS

#include <mbedtls/debug.h>
#include <mbedtls/ecp.h>
#include <mbedtls/net.h>
#include <mbedtls/platform.h>
#include <mbedtls/ssl.h>
#include <mbedtls/ssl_internal.h>
#include <mbedtls/x509_crt.h>
#include <mbedtls/version.h>

static void mg_ssl_mbed_log(void *ctx, int level, const char *file, int line,
    const char *str) {
    enum cs_log_level cs_level;
    switch (level) {
    case 1:
        cs_level = LL_ERROR;
        break;
    case 2:
        cs_level = LL_INFO;
        break;
    case 3:
        cs_level = LL_DEBUG;
        break;
    default:
        cs_level = LL_VERBOSE_DEBUG;
    }
    /* mbedTLS passes strings with \n at the end, strip it. */
    LOG(cs_level, ("%p %.*s", ctx, (int)(strlen(str) - 1), str));
    (void)ctx;
    (void)str;
    (void)file;
    (void)line;
    (void)cs_level;
}

struct mg_ssl_if_ctx {
    mbedtls_ssl_config *conf;
    mbedtls_ssl_context *ssl;
    mbedtls_x509_crt *cert;
    mbedtls_pk_context *key;
    mbedtls_x509_crt *ca_cert;
    struct mbuf cipher_suites;
    size_t saved_len;
};

/* Must be provided by the platform. ctx is struct mg_connection. */
extern int mg_ssl_if_mbed_random(void *ctx, unsigned char *buf, size_t len);

void mg_ssl_if_init() {
    LOG(LL_INFO, ("%s", MBEDTLS_VERSION_STRING_FULL));
}

enum mg_ssl_if_result mg_ssl_if_conn_accept(struct mg_connection *nc,
    struct mg_connection *lc) {
    struct mg_ssl_if_ctx *ctx =
        (struct mg_ssl_if_ctx *) MG_CALLOC(1, sizeof(*ctx));
    struct mg_ssl_if_ctx *lc_ctx = (struct mg_ssl_if_ctx *) lc->ssl_if_data;
    nc->ssl_if_data = ctx;
    if (ctx == NULL || lc_ctx == NULL) return MG_SSL_ERROR;
    ctx->ssl = (mbedtls_ssl_context *)MG_CALLOC(1, sizeof(*ctx->ssl));
    if (mbedtls_ssl_setup(ctx->ssl, lc_ctx->conf) != 0) {
        return MG_SSL_ERROR;
    }
    return MG_SSL_OK;
}

static enum mg_ssl_if_result mg_use_cert(struct mg_ssl_if_ctx *ctx,
    const char *cert, const char *key,
    const char **err_msg);
static enum mg_ssl_if_result mg_use_ca_cert(struct mg_ssl_if_ctx *ctx,
    const char *cert);
static enum mg_ssl_if_result mg_set_cipher_list(struct mg_ssl_if_ctx *ctx,
    const char *ciphers);
#ifdef MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED
static enum mg_ssl_if_result mg_ssl_if_mbed_set_psk(struct mg_ssl_if_ctx *ctx,
    const char *identity,
    const char *key);
#endif

enum mg_ssl_if_result mg_ssl_if_conn_init(
    struct mg_connection *nc, const struct mg_ssl_if_conn_params *params,
    const char **err_msg) {
    struct mg_ssl_if_ctx *ctx =
        (struct mg_ssl_if_ctx *) MG_CALLOC(1, sizeof(*ctx));
    DBG(("%p %s,%s,%s", nc, (params->cert ? params->cert : ""),
        (params->key ? params->key : ""),
        (params->ca_cert ? params->ca_cert : "")));

    if (ctx == NULL) {
        MG_SET_PTRPTR(err_msg, "Out of memory");
        return MG_SSL_ERROR;
    }
    nc->ssl_if_data = ctx;
    ctx->conf = (mbedtls_ssl_config *)MG_CALLOC(1, sizeof(*ctx->conf));
    mbuf_init(&ctx->cipher_suites, 0);
    mbedtls_ssl_config_init(ctx->conf);
    mbedtls_ssl_conf_dbg(ctx->conf, mg_ssl_mbed_log, nc);
    if (mbedtls_ssl_config_defaults(
        ctx->conf, (nc->flags & MG_F_LISTENING ? MBEDTLS_SSL_IS_SERVER
            : MBEDTLS_SSL_IS_CLIENT),
        MBEDTLS_SSL_TRANSPORT_STREAM, MBEDTLS_SSL_PRESET_DEFAULT) != 0) {
        MG_SET_PTRPTR(err_msg, "Failed to init SSL config");
        return MG_SSL_ERROR;
    }

    /* TLS 1.2 and up */
    mbedtls_ssl_conf_min_version(ctx->conf, MBEDTLS_SSL_MAJOR_VERSION_3,
        MBEDTLS_SSL_MINOR_VERSION_3);
    mbedtls_ssl_conf_rng(ctx->conf, mg_ssl_if_mbed_random, nc);

    if (params->cert != NULL &&
        mg_use_cert(ctx, params->cert, params->key, err_msg) != MG_SSL_OK) {
        return MG_SSL_ERROR;
    }

    if (params->ca_cert != NULL &&
        mg_use_ca_cert(ctx, params->ca_cert) != MG_SSL_OK) {
        MG_SET_PTRPTR(err_msg, "Invalid SSL CA cert");
        return MG_SSL_ERROR;
    }

    if (mg_set_cipher_list(ctx, params->cipher_suites) != MG_SSL_OK) {
        MG_SET_PTRPTR(err_msg, "Invalid cipher suite list");
        return MG_SSL_ERROR;
    }

#ifdef MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED
    if (mg_ssl_if_mbed_set_psk(ctx, params->psk_identity, params->psk_key) !=
        MG_SSL_OK) {
        MG_SET_PTRPTR(err_msg, "Invalid PSK settings");
        return MG_SSL_ERROR;
    }
#endif

    if (!(nc->flags & MG_F_LISTENING)) {
        ctx->ssl = (mbedtls_ssl_context *)MG_CALLOC(1, sizeof(*ctx->ssl));
        mbedtls_ssl_init(ctx->ssl);
        if (mbedtls_ssl_setup(ctx->ssl, ctx->conf) != 0) {
            MG_SET_PTRPTR(err_msg, "Failed to create SSL session");
            return MG_SSL_ERROR;
        }
        if (params->server_name != NULL &&
            mbedtls_ssl_set_hostname(ctx->ssl, params->server_name) != 0) {
            return MG_SSL_ERROR;
        }
    }

#ifdef MG_SSL_IF_MBEDTLS_MAX_FRAG_LEN
    if (mbedtls_ssl_conf_max_frag_len(ctx->conf,
#if MG_SSL_IF_MBEDTLS_MAX_FRAG_LEN == 512
        MBEDTLS_SSL_MAX_FRAG_LEN_512
#elif MG_SSL_IF_MBEDTLS_MAX_FRAG_LEN == 1024
        MBEDTLS_SSL_MAX_FRAG_LEN_1024
#elif MG_SSL_IF_MBEDTLS_MAX_FRAG_LEN == 2048
        MBEDTLS_SSL_MAX_FRAG_LEN_2048
#elif MG_SSL_IF_MBEDTLS_MAX_FRAG_LEN == 4096
        MBEDTLS_SSL_MAX_FRAG_LEN_4096
#else
#error Invalid MG_SSL_IF_MBEDTLS_MAX_FRAG_LEN
#endif
    ) != 0) {
        return MG_SSL_ERROR;
    }
#endif

    nc->flags |= MG_F_SSL;

    return MG_SSL_OK;
}

static int mg_ssl_if_mbed_send(void *ctx, const unsigned char *buf,
    size_t len) {
    struct mg_connection *nc = (struct mg_connection *) ctx;
    int n = nc->iface->vtable->tcp_send(nc, buf, len);
    if (n > 0) return n;
    if (n == 0) return MBEDTLS_ERR_SSL_WANT_WRITE;
    return MBEDTLS_ERR_NET_SEND_FAILED;
}

static int mg_ssl_if_mbed_recv(void *ctx, unsigned char *buf, size_t len) {
    struct mg_connection *nc = (struct mg_connection *) ctx;
    int n = nc->iface->vtable->tcp_recv(nc, buf, len);
    if (n > 0) return n;
    if (n == 0) return MBEDTLS_ERR_SSL_WANT_READ;
    return MBEDTLS_ERR_NET_RECV_FAILED;
}

static enum mg_ssl_if_result mg_ssl_if_mbed_err(struct mg_connection *nc,
    int ret) {
    enum mg_ssl_if_result res = MG_SSL_OK;
    if (ret == MBEDTLS_ERR_SSL_WANT_READ) {
        res = MG_SSL_WANT_READ;
    }
    else if (ret == MBEDTLS_ERR_SSL_WANT_WRITE) {
        res = MG_SSL_WANT_WRITE;
    }
    else if (ret == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY) {
        LOG(LL_DEBUG, ("%p TLS connection closed by peer", nc));
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        res = MG_SSL_OK;
    }
    else {
        LOG(LL_ERROR, ("%p mbedTLS error: -0x%04x", nc, -ret));
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        res = MG_SSL_ERROR;
    }
    nc->err = ret;
    return res;
}

static void mg_ssl_if_mbed_free_certs_and_keys(struct mg_ssl_if_ctx *ctx) {
    if (ctx->cert != NULL) {
        mbedtls_x509_crt_free(ctx->cert);
        MG_FREE(ctx->cert);
        ctx->cert = NULL;
        mbedtls_pk_free(ctx->key);
        MG_FREE(ctx->key);
        ctx->key = NULL;
    }
    if (ctx->ca_cert != NULL) {
        mbedtls_ssl_conf_ca_chain(ctx->conf, NULL, NULL);
#ifdef MBEDTLS_X509_CA_CHAIN_ON_DISK
        if (ctx->conf->ca_chain_file != NULL) {
            MG_FREE((void *)ctx->conf->ca_chain_file);
            ctx->conf->ca_chain_file = NULL;
        }
#endif
        mbedtls_x509_crt_free(ctx->ca_cert);
        MG_FREE(ctx->ca_cert);
        ctx->ca_cert = NULL;
    }
}

enum mg_ssl_if_result mg_ssl_if_handshake(struct mg_connection *nc) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    int err;
    /* If bio is not yet set, do it now. */
    if (ctx->ssl->p_bio == NULL) {
        mbedtls_ssl_set_bio(ctx->ssl, nc, mg_ssl_if_mbed_send, mg_ssl_if_mbed_recv,
            NULL);
    }
    err = mbedtls_ssl_handshake(ctx->ssl);
    if (err != 0) return mg_ssl_if_mbed_err(nc, err);
#ifdef MG_SSL_IF_MBEDTLS_FREE_CERTS
    /*
     * Free the peer certificate, we don't need it after handshake.
     * Note that this effectively disables renegotiation.
     */
    mbedtls_x509_crt_free(ctx->ssl->session->peer_cert);
    mbedtls_free(ctx->ssl->session->peer_cert);
    ctx->ssl->session->peer_cert = NULL;
    /* On a client connection we can also free our own and CA certs. */
    if (nc->listener == NULL) {
        if (ctx->conf->key_cert != NULL) {
            /* Note that this assumes one key_cert entry, which matches our init. */
            MG_FREE(ctx->conf->key_cert);
            ctx->conf->key_cert = NULL;
        }
        mbedtls_ssl_conf_ca_chain(ctx->conf, NULL, NULL);
        mg_ssl_if_mbed_free_certs_and_keys(ctx);
    }
#endif
    return MG_SSL_OK;
}

int mg_ssl_if_read(struct mg_connection *nc, void *buf, size_t len) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    int n = mbedtls_ssl_read(ctx->ssl, (unsigned char *)buf, len);
    DBG(("%p %d -> %d", nc, (int)len, n));
    if (n < 0) return mg_ssl_if_mbed_err(nc, n);
    if (n == 0) nc->flags |= MG_F_CLOSE_IMMEDIATELY;
    return n;
}

int mg_ssl_if_write(struct mg_connection *nc, const void *buf, size_t len) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    /* Per mbedTLS docs, if write returns WANT_READ or WANT_WRITE, the operation
     * should be retried with the same data and length.
     * Here we assume that the data being pushed will remain the same but the
     * amount may grow between calls so we save the length that was used and
     * retry. The assumption being that the data itself won't change and won't
     * be removed. */
    size_t l = len;
    if (ctx->saved_len > 0 && ctx->saved_len < l) l = ctx->saved_len;
    int n = mbedtls_ssl_write(ctx->ssl, (const unsigned char *)buf, l);
    DBG(("%p %d,%d,%d -> %d", nc, (int)len, (int)ctx->saved_len, (int)l, n));
    if (n < 0) {
        if (n == MBEDTLS_ERR_SSL_WANT_READ || n == MBEDTLS_ERR_SSL_WANT_WRITE) {
            ctx->saved_len = len;
        }
        return mg_ssl_if_mbed_err(nc, n);
    }
    else if (n > 0) {
        ctx->saved_len = 0;
    }
    return n;
}

void mg_ssl_if_conn_close_notify(struct mg_connection *nc) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    if (ctx == NULL) return;
    mbedtls_ssl_close_notify(ctx->ssl);
}

void mg_ssl_if_conn_free(struct mg_connection *nc) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    if (ctx == NULL) return;
    nc->ssl_if_data = NULL;
    if (ctx->ssl != NULL) {
        mbedtls_ssl_free(ctx->ssl);
        MG_FREE(ctx->ssl);
    }
    mg_ssl_if_mbed_free_certs_and_keys(ctx);
    if (ctx->conf != NULL) {
        mbedtls_ssl_config_free(ctx->conf);
        MG_FREE(ctx->conf);
    }
    mbuf_free(&ctx->cipher_suites);
    memset(ctx, 0, sizeof(*ctx));
    MG_FREE(ctx);
}

static enum mg_ssl_if_result mg_use_ca_cert(struct mg_ssl_if_ctx *ctx,
    const char *ca_cert) {
    if (ca_cert == NULL || strcmp(ca_cert, "*") == 0) {
        mbedtls_ssl_conf_authmode(ctx->conf, MBEDTLS_SSL_VERIFY_NONE);
        return MG_SSL_OK;
    }
    ctx->ca_cert = (mbedtls_x509_crt *)MG_CALLOC(1, sizeof(*ctx->ca_cert));
    mbedtls_x509_crt_init(ctx->ca_cert);
#ifdef MBEDTLS_X509_CA_CHAIN_ON_DISK
    ca_cert = strdup(ca_cert);
    mbedtls_ssl_conf_ca_chain_file(ctx->conf, ca_cert, NULL);
#else
    if (mbedtls_x509_crt_parse_file(ctx->ca_cert, ca_cert) != 0) {
        return MG_SSL_ERROR;
    }
    mbedtls_ssl_conf_ca_chain(ctx->conf, ctx->ca_cert, NULL);
#endif
    mbedtls_ssl_conf_authmode(ctx->conf, MBEDTLS_SSL_VERIFY_REQUIRED);
    return MG_SSL_OK;
}

static enum mg_ssl_if_result mg_use_cert(struct mg_ssl_if_ctx *ctx,
    const char *cert, const char *key,
    const char **err_msg) {
    if (key == NULL) key = cert;
    if (cert == NULL || cert[0] == '\0' || key == NULL || key[0] == '\0') {
        return MG_SSL_OK;
    }
    ctx->cert = (mbedtls_x509_crt *)MG_CALLOC(1, sizeof(*ctx->cert));
    mbedtls_x509_crt_init(ctx->cert);
    ctx->key = (mbedtls_pk_context *)MG_CALLOC(1, sizeof(*ctx->key));
    mbedtls_pk_init(ctx->key);
    if (mbedtls_x509_crt_parse_file(ctx->cert, cert) != 0) {
        MG_SET_PTRPTR(err_msg, "Invalid SSL cert");
        return MG_SSL_ERROR;
    }
    if (mbedtls_pk_parse_keyfile(ctx->key, key, NULL) != 0) {
        MG_SET_PTRPTR(err_msg, "Invalid SSL key");
        return MG_SSL_ERROR;
    }
    if (mbedtls_ssl_conf_own_cert(ctx->conf, ctx->cert, ctx->key) != 0) {
        MG_SET_PTRPTR(err_msg, "Invalid SSL key or cert");
        return MG_SSL_ERROR;
    }
    return MG_SSL_OK;
}

static const int mg_s_cipher_list[] = {
#if CS_PLATFORM != CS_P_ESP8266
    MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
    MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
    MBEDTLS_TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
    MBEDTLS_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
    MBEDTLS_TLS_DHE_RSA_WITH_AES_128_GCM_SHA256,
    MBEDTLS_TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,
    MBEDTLS_TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256,
    MBEDTLS_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256,
    MBEDTLS_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA,
    MBEDTLS_TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256,
    MBEDTLS_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256,
    MBEDTLS_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA,
    MBEDTLS_TLS_RSA_WITH_AES_128_GCM_SHA256,
    MBEDTLS_TLS_RSA_WITH_AES_128_CBC_SHA256,
    MBEDTLS_TLS_RSA_WITH_AES_128_CBC_SHA,
#else
    /*
     * ECDHE is way too slow on ESP8266 w/o cryptochip, this sometimes results
     * in WiFi STA deauths. Use weaker but faster cipher suites. Sad but true.
     * Disable DHE completely because it's just hopelessly slow.
     */
    MBEDTLS_TLS_RSA_WITH_AES_128_GCM_SHA256,
    MBEDTLS_TLS_RSA_WITH_AES_128_CBC_SHA256,
    MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
    MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
    MBEDTLS_TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
    MBEDTLS_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
    MBEDTLS_TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256,
    MBEDTLS_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256,
    MBEDTLS_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA,
    MBEDTLS_TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256,
    MBEDTLS_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256,
    MBEDTLS_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA,
    MBEDTLS_TLS_RSA_WITH_AES_128_CBC_SHA,
#endif /* CS_PLATFORM != CS_P_ESP8266 */
    0,
};

/*
 * Ciphers can be specified as a colon-separated list of cipher suite names.
 * These can be found in
 * https://github.com/ARMmbed/mbedtls/blob/development/library/ssl_ciphersuites.c#L267
 * E.g.: TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256:TLS-DHE-RSA-WITH-AES-256-CCM
 */
static enum mg_ssl_if_result mg_set_cipher_list(struct mg_ssl_if_ctx *ctx,
    const char *ciphers) {
    if (ciphers != NULL) {
        int l, id;
        const char *s = ciphers, *e;
        char tmp[50];
        while (s != NULL) {
            e = strchr(s, ':');
            l = (e != NULL ? (e - s) : (int)strlen(s));
            strncpy(tmp, s, l);
            tmp[l] = '\0';
            id = mbedtls_ssl_get_ciphersuite_id(tmp);
            DBG(("%s -> %04x", tmp, id));
            if (id != 0) {
                mbuf_append(&ctx->cipher_suites, &id, sizeof(id));
            }
            s = (e != NULL ? e + 1 : NULL);
        }
        if (ctx->cipher_suites.len == 0) return MG_SSL_ERROR;
        id = 0;
        mbuf_append(&ctx->cipher_suites, &id, sizeof(id));
        mbuf_trim(&ctx->cipher_suites);
        mbedtls_ssl_conf_ciphersuites(ctx->conf,
            (const int *)ctx->cipher_suites.buf);
    }
    else {
        mbedtls_ssl_conf_ciphersuites(ctx->conf, mg_s_cipher_list);
    }
    return MG_SSL_OK;
}

#ifdef MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED
static enum mg_ssl_if_result mg_ssl_if_mbed_set_psk(struct mg_ssl_if_ctx *ctx,
    const char *identity,
    const char *key_str) {
    unsigned char key[32];
    size_t key_len;
    if (identity == NULL && key_str == NULL) return MG_SSL_OK;
    if (identity == NULL || key_str == NULL) return MG_SSL_ERROR;
    key_len = strlen(key_str);
    if (key_len != 32 && key_len != 64) return MG_SSL_ERROR;
    size_t i = 0;
    memset(key, 0, sizeof(key));
    key_len = 0;
    for (i = 0; key_str[i] != '\0'; i++) {
        unsigned char c;
        char hc = tolower((int)key_str[i]);
        if (hc >= '0' && hc <= '9') {
            c = hc - '0';
        }
        else if (hc >= 'a' && hc <= 'f') {
            c = hc - 'a' + 0xa;
        }
        else {
            return MG_SSL_ERROR;
        }
        key_len = i / 2;
        key[key_len] <<= 4;
        key[key_len] |= c;
    }
    key_len++;
    DBG(("identity = '%s', key = (%u)", identity, (unsigned int)key_len));
    /* mbedTLS makes copies of psk and identity. */
    if (mbedtls_ssl_conf_psk(ctx->conf, (const unsigned char *)key, key_len,
        (const unsigned char *)identity,
        strlen(identity)) != 0) {
        return MG_SSL_ERROR;
    }
    return MG_SSL_OK;
}
#endif

const char *mg_set_ssl(struct mg_connection *nc, const char *cert,
    const char *ca_cert) {
    const char *err_msg = NULL;
    struct mg_ssl_if_conn_params params;
    memset(&params, 0, sizeof(params));
    params.cert = cert;
    params.ca_cert = ca_cert;
    if (mg_ssl_if_conn_init(nc, &params, &err_msg) != MG_SSL_OK) {
        return err_msg;
    }
    return NULL;
}

/* Lazy RNG. Warning: it would be a bad idea to do this in production! */
#ifdef MG_SSL_MBED_DUMMY_RANDOM
int mg_ssl_if_mbed_random(void *ctx, unsigned char *buf, size_t len) {
    (void)ctx;
    while (len--) *buf++ = rand();
    return 0;
}
#endif

#endif /* MG_ENABLE_SSL && MG_SSL_IF == MG_SSL_IF_MBEDTLS */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_uri.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "mg_uri.h" */

 /*
  * scan string until encountering one of `seps`, keeping track of component
  * boundaries in `res`.
  *
  * `p` will point to the char after the separator or it will be `end`.
  */
static void parse_uri_component(const char **p, const char *end,
    const char *seps, struct mg_str *res) {
    const char *q;
    res->p = *p;
    for (; *p < end; (*p)++) {
        for (q = seps; *q != '\0'; q++) {
            if (**p == *q) break;
        }
        if (*q != '\0') break;
    }
    res->len = (*p) - res->p;
    if (*p < end) (*p)++;
}

int mg_parse_uri(const struct mg_str uri, struct mg_str *scheme,
    struct mg_str *user_info, struct mg_str *host,
    unsigned int *port, struct mg_str *path, struct mg_str *query,
    struct mg_str *fragment) {
    struct mg_str rscheme = { 0, 0 }, ruser_info = { 0, 0 }, rhost = { 0, 0 },
        rpath = { 0, 0 }, rquery = { 0, 0 }, rfragment = { 0, 0 };
    unsigned int rport = 0;
    enum {
        P_START,
        P_SCHEME_OR_PORT,
        P_USER_INFO,
        P_HOST,
        P_PORT,
        P_REST
    } state = P_START;

    const char *p = uri.p, *end = p + uri.len;
    while (p < end) {
        switch (state) {
        case P_START:
            /*
             * expecting on of:
             * - `scheme://xxxx`
             * - `xxxx:port`
             * - `[a:b:c]:port`
             * - `xxxx/path`
             */
            if (*p == '[') {
                state = P_HOST;
                break;
            }
            for (; p < end; p++) {
                if (*p == ':') {
                    state = P_SCHEME_OR_PORT;
                    break;
                }
                else if (*p == '/') {
                    state = P_REST;
                    break;
                }
            }
            if (state == P_START || state == P_REST) {
                rhost.p = uri.p;
                rhost.len = p - uri.p;
            }
            break;
        case P_SCHEME_OR_PORT:
            if (end - p >= 3 && strncmp(p, "://", 3) == 0) {
                rscheme.p = uri.p;
                rscheme.len = p - uri.p;
                state = P_USER_INFO;
                p += 3;
            }
            else {
                rhost.p = uri.p;
                rhost.len = p - uri.p;
                state = P_PORT;
            }
            break;
        case P_USER_INFO:
            ruser_info.p = p;
            for (; p < end; p++) {
                if (*p == '@' || *p == '[' || *p == '/') {
                    break;
                }
            }
            if (p == end || *p == '/' || *p == '[') {
                /* backtrack and parse as host */
                p = ruser_info.p;
            }
            ruser_info.len = p - ruser_info.p;
            state = P_HOST;
            break;
        case P_HOST:
            if (*p == '@') p++;
            rhost.p = p;
            if (*p == '[') {
                int found = 0;
                for (; !found && p < end; p++) {
                    found = (*p == ']');
                }
                if (!found) return -1;
            }
            else {
                for (; p < end; p++) {
                    if (*p == ':' || *p == '/') break;
                }
            }
            rhost.len = p - rhost.p;
            if (p < end) {
                if (*p == ':') {
                    state = P_PORT;
                    break;
                }
                else if (*p == '/') {
                    state = P_REST;
                    break;
                }
            }
            break;
        case P_PORT:
            p++;
            for (; p < end; p++) {
                if (*p == '/') {
                    state = P_REST;
                    break;
                }
                rport *= 10;
                rport += *p - '0';
            }
            break;
        case P_REST:
            /* `p` points to separator. `path` includes the separator */
            parse_uri_component(&p, end, "?#", &rpath);
            if (p < end && *(p - 1) == '?') {
                parse_uri_component(&p, end, "#", &rquery);
            }
            parse_uri_component(&p, end, "", &rfragment);
            break;
        }
    }

    if (scheme != 0) *scheme = rscheme;
    if (user_info != 0) *user_info = ruser_info;
    if (host != 0) *host = rhost;
    if (port != 0) *port = rport;
    if (path != 0) *path = rpath;
    if (query != 0) *query = rquery;
    if (fragment != 0) *fragment = rfragment;

    return 0;
}

/* Normalize the URI path. Remove/resolve "." and "..". */
int mg_normalize_uri_path(const struct mg_str *in, struct mg_str *out) {
    const char *s = in->p, *se = s + in->len;
    char *cp = (char *)out->p, *d;

    if (in->len == 0 || *s != '/') {
        out->len = 0;
        return 0;
    }

    d = cp;

    while (s < se) {
        const char *next = s;
        struct mg_str component;
        parse_uri_component(&next, se, "/", &component);
        if (mg_vcmp(&component, ".") == 0) {
            /* Yum. */
        }
        else if (mg_vcmp(&component, "..") == 0) {
            /* Backtrack to previous slash. */
            if (d > cp + 1 && *(d - 1) == '/') d--;
            while (d > cp && *(d - 1) != '/') d--;
        }
        else {
            memmove(d, s, next - s);
            d += next - s;
        }
        s = next;
    }
    if (d == cp) *d++ = '/';

    out->p = cp;
    out->len = d - cp;
    return 1;
}

int mg_assemble_uri(const struct mg_str *scheme, const struct mg_str *user_info,
    const struct mg_str *host, unsigned int port,
    const struct mg_str *path, const struct mg_str *query,
    const struct mg_str *fragment, int normalize_path,
    struct mg_str *uri) {
    int result = -1;
    struct mbuf out;
    mbuf_init(&out, 0);

    if (scheme != NULL && scheme->len > 0) {
        mbuf_append(&out, scheme->p, scheme->len);
        mbuf_append(&out, "://", 3);
    }

    if (user_info != NULL && user_info->len > 0) {
        mbuf_append(&out, user_info->p, user_info->len);
        mbuf_append(&out, "@", 1);
    }

    if (host != NULL && host->len > 0) {
        mbuf_append(&out, host->p, host->len);
    }

    if (port != 0) {
        char port_str[20];
        int port_str_len = sprintf(port_str, ":%u", port);
        mbuf_append(&out, port_str, port_str_len);
    }

    if (path != NULL && path->len > 0) {
        if (normalize_path) {
            struct mg_str npath = mg_strdup(*path);
            if (npath.len != path->len) goto out;
            if (!mg_normalize_uri_path(path, &npath)) {
                free((void *)npath.p);
                goto out;
            }
            mbuf_append(&out, npath.p, npath.len);
            free((void *)npath.p);
        }
        else {
            mbuf_append(&out, path->p, path->len);
        }
    }
    else if (normalize_path) {
        mbuf_append(&out, "/", 1);
    }

    if (query != NULL && query->len > 0) {
        mbuf_append(&out, "?", 1);
        mbuf_append(&out, query->p, query->len);
    }

    if (fragment != NULL && fragment->len > 0) {
        mbuf_append(&out, "#", 1);
        mbuf_append(&out, fragment->p, fragment->len);
    }

    result = 0;

out:
    if (result == 0) {
        uri->p = out.buf;
        uri->len = out.len;
    }
    else {
        mbuf_free(&out);
        uri->p = NULL;
        uri->len = 0;
    }
    return result;
}
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_http.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_HTTP

 /* Amalgamated: #include "common/cs_md5.h" */
 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "mg_util.h" */

 /* altbuf {{{ */

 /*
  * Alternate buffer: fills the client-provided buffer with data; and if it's
  * not large enough, allocates another buffer (via mbuf), similar to asprintf.
  */
struct altbuf {
    struct mbuf m;
    char *user_buf;
    size_t len;
    size_t user_buf_size;
};

/*
 * Initializes altbuf; `buf`, `buf_size` is the client-provided buffer.
 */
MG_INTERNAL void altbuf_init(struct altbuf *ab, char *buf, size_t buf_size) {
    mbuf_init(&ab->m, 0);
    ab->user_buf = buf;
    ab->user_buf_size = buf_size;
    ab->len = 0;
}

/*
 * Appends a single char to the altbuf.
 */
MG_INTERNAL void altbuf_append(struct altbuf *ab, char c) {
    if (ab->len < ab->user_buf_size) {
        /* The data fits into the original buffer */
        ab->user_buf[ab->len++] = c;
    }
    else {
        /* The data can't fit into the original buffer, so write it to mbuf.  */

        /*
         * First of all, see if that's the first byte which overflows the original
         * buffer: if so, copy the existing data from there to a newly allocated
         * mbuf.
         */
        if (ab->len > 0 && ab->m.len == 0) {
            mbuf_append(&ab->m, ab->user_buf, ab->len);
        }

        mbuf_append(&ab->m, &c, 1);
        ab->len = ab->m.len;
    }
}

/*
 * Resets any data previously appended to altbuf.
 */
MG_INTERNAL void altbuf_reset(struct altbuf *ab) {
    mbuf_free(&ab->m);
    ab->len = 0;
}

/*
 * Returns whether the additional buffer was allocated (and thus the data
 * is in the mbuf, not the client-provided buffer)
 */
MG_INTERNAL int altbuf_reallocated(struct altbuf *ab) {
    return ab->len > ab->user_buf_size;
}

/*
 * Returns the actual buffer with data, either the client-provided or a newly
 * allocated one. If `trim` is non-zero, mbuf-backed buffer is trimmed first.
 */
MG_INTERNAL char *altbuf_get_buf(struct altbuf *ab, int trim) {
    if (altbuf_reallocated(ab)) {
        if (trim) {
            mbuf_trim(&ab->m);
        }
        return ab->m.buf;
    }
    else {
        return ab->user_buf;
    }
}

/* }}} */

static const char *mg_version_header = "Mongoose/" MG_VERSION;

enum mg_http_proto_data_type { DATA_NONE, DATA_FILE, DATA_PUT };

struct mg_http_proto_data_file {
    FILE *fp;      /* Opened file. */
    int64_t cl;    /* Content-Length. How many bytes to send. */
    int64_t sent;  /* How many bytes have been already sent. */
    int keepalive; /* Keep connection open after sending. */
    enum mg_http_proto_data_type type;
};

#if MG_ENABLE_HTTP_CGI
struct mg_http_proto_data_cgi {
    struct mg_connection *cgi_nc;
};
#endif

struct mg_http_proto_data_chuncked {
    int64_t body_len; /* How many bytes of chunked body was reassembled. */
};

struct mg_http_endpoint {
    struct mg_http_endpoint *next;
    struct mg_str uri_pattern; /* owned */
    char *auth_domain;         /* owned */
    char *auth_file;           /* owned */

    mg_event_handler_t handler;
#if MG_ENABLE_CALLBACK_USERDATA
    void *user_data;
#endif
};

enum mg_http_multipart_stream_state {
    MPS_BEGIN,
    MPS_WAITING_FOR_BOUNDARY,
    MPS_WAITING_FOR_CHUNK,
    MPS_GOT_BOUNDARY,
    MPS_FINALIZE,
    MPS_FINISHED
};

struct mg_http_multipart_stream {
    const char *boundary;
    int boundary_len;
    const char *var_name;
    const char *file_name;
    void *user_data;
    enum mg_http_multipart_stream_state state;
    int processing_part;
    int data_avail;
};

struct mg_reverse_proxy_data {
    struct mg_connection *linked_conn;
};

struct mg_ws_proto_data {
    /*
     * Defragmented size of the frame so far.
     *
     * First byte of nc->recv_mbuf.buf is an op, the rest of the data is
     * defragmented data.
     */
    size_t reass_len;
};

struct mg_http_proto_data {
#if MG_ENABLE_FILESYSTEM
    struct mg_http_proto_data_file file;
#endif
#if MG_ENABLE_HTTP_CGI
    struct mg_http_proto_data_cgi cgi;
#endif
#if MG_ENABLE_HTTP_STREAMING_MULTIPART
    struct mg_http_multipart_stream mp_stream;
#endif
#if MG_ENABLE_HTTP_WEBSOCKET
    struct mg_ws_proto_data ws_data;
#endif
    struct mg_http_proto_data_chuncked chunk;
    struct mg_http_endpoint *endpoints;
    mg_event_handler_t endpoint_handler;
    struct mg_reverse_proxy_data reverse_proxy_data;
    size_t rcvd; /* How many bytes we have received. */
};

static void mg_http_proto_data_destructor(void *proto_data);

struct mg_connection *mg_connect_http_base(
    struct mg_mgr *mgr, MG_CB(mg_event_handler_t ev_handler, void *user_data),
    struct mg_connect_opts opts, const char *scheme1, const char *scheme2,
    const char *scheme_ssl1, const char *scheme_ssl2, const char *url,
    struct mg_str *path, struct mg_str *user_info, struct mg_str *host);

MG_INTERNAL struct mg_http_proto_data *mg_http_create_proto_data(
    struct mg_connection *c) {
    /* If we have proto data from previous connection, flush it. */
    if (c->proto_data != NULL) {
        void *pd = c->proto_data;
        c->proto_data = NULL;
        mg_http_proto_data_destructor(pd);
    }
    c->proto_data = MG_CALLOC(1, sizeof(struct mg_http_proto_data));
    c->proto_data_destructor = mg_http_proto_data_destructor;
    return (struct mg_http_proto_data *) c->proto_data;
}

static struct mg_http_proto_data *mg_http_get_proto_data(
    struct mg_connection *c) {
    return (struct mg_http_proto_data *) c->proto_data;
}

#if MG_ENABLE_HTTP_STREAMING_MULTIPART
static void mg_http_free_proto_data_mp_stream(
    struct mg_http_multipart_stream *mp) {
    MG_FREE((void *)mp->boundary);
    MG_FREE((void *)mp->var_name);
    MG_FREE((void *)mp->file_name);
    memset(mp, 0, sizeof(*mp));
}
#endif

#if MG_ENABLE_FILESYSTEM
static void mg_http_free_proto_data_file(struct mg_http_proto_data_file *d) {
    if (d != NULL) {
        if (d->fp != NULL) {
            fclose(d->fp);
        }
        memset(d, 0, sizeof(struct mg_http_proto_data_file));
    }
}
#endif

static void mg_http_free_proto_data_endpoints(struct mg_http_endpoint **ep) {
    struct mg_http_endpoint *current = *ep;

    while (current != NULL) {
        struct mg_http_endpoint *tmp = current->next;
        MG_FREE((void *)current->uri_pattern.p);
        MG_FREE((void *)current->auth_domain);
        MG_FREE((void *)current->auth_file);
        MG_FREE(current);
        current = tmp;
    }

    ep = NULL;
}

static void mg_http_free_reverse_proxy_data(struct mg_reverse_proxy_data *rpd) {
    if (rpd->linked_conn != NULL) {
        /*
         * Connection has linked one, we have to unlink & close it
         * since _this_ connection is going to die and
         * it doesn't make sense to keep another one
         */
        struct mg_http_proto_data *pd = mg_http_get_proto_data(rpd->linked_conn);
        if (pd->reverse_proxy_data.linked_conn != NULL) {
            pd->reverse_proxy_data.linked_conn->flags |= MG_F_SEND_AND_CLOSE;
            pd->reverse_proxy_data.linked_conn = NULL;
        }
        rpd->linked_conn = NULL;
    }
}

static void mg_http_proto_data_destructor(void *proto_data) {
    struct mg_http_proto_data *pd = (struct mg_http_proto_data *) proto_data;
#if MG_ENABLE_FILESYSTEM
    mg_http_free_proto_data_file(&pd->file);
#endif
#if MG_ENABLE_HTTP_CGI
    mg_http_free_proto_data_cgi(&pd->cgi);
#endif
#if MG_ENABLE_HTTP_STREAMING_MULTIPART
    mg_http_free_proto_data_mp_stream(&pd->mp_stream);
#endif
    mg_http_free_proto_data_endpoints(&pd->endpoints);
    mg_http_free_reverse_proxy_data(&pd->reverse_proxy_data);
    MG_FREE(proto_data);
}

#if MG_ENABLE_FILESYSTEM

#define MIME_ENTRY(_ext, _type) \
  { _ext, sizeof(_ext) - 1, _type }
static const struct {
    const char *extension;
    size_t ext_len;
    const char *mime_type;
} mg_static_builtin_mime_types[] = {
    MIME_ENTRY("html", "text/html"),
    MIME_ENTRY("html", "text/html"),
    MIME_ENTRY("htm", "text/html"),
    MIME_ENTRY("shtm", "text/html"),
    MIME_ENTRY("shtml", "text/html"),
    MIME_ENTRY("css", "text/css"),
    MIME_ENTRY("js", "application/x-javascript"),
    MIME_ENTRY("ico", "image/x-icon"),
    MIME_ENTRY("gif", "image/gif"),
    MIME_ENTRY("jpg", "image/jpeg"),
    MIME_ENTRY("jpeg", "image/jpeg"),
    MIME_ENTRY("png", "image/png"),
    MIME_ENTRY("svg", "image/svg+xml"),
    MIME_ENTRY("txt", "text/plain"),
    MIME_ENTRY("torrent", "application/x-bittorrent"),
    MIME_ENTRY("wav", "audio/x-wav"),
    MIME_ENTRY("mp3", "audio/x-mp3"),
    MIME_ENTRY("mid", "audio/mid"),
    MIME_ENTRY("m3u", "audio/x-mpegurl"),
    MIME_ENTRY("ogg", "application/ogg"),
    MIME_ENTRY("ram", "audio/x-pn-realaudio"),
    MIME_ENTRY("xml", "text/xml"),
    MIME_ENTRY("ttf", "application/x-font-ttf"),
    MIME_ENTRY("json", "application/json"),
    MIME_ENTRY("xslt", "application/xml"),
    MIME_ENTRY("xsl", "application/xml"),
    MIME_ENTRY("ra", "audio/x-pn-realaudio"),
    MIME_ENTRY("doc", "application/msword"),
    MIME_ENTRY("exe", "application/octet-stream"),
    MIME_ENTRY("zip", "application/x-zip-compressed"),
    MIME_ENTRY("xls", "application/excel"),
    MIME_ENTRY("tgz", "application/x-tar-gz"),
    MIME_ENTRY("tar", "application/x-tar"),
    MIME_ENTRY("gz", "application/x-gunzip"),
    MIME_ENTRY("arj", "application/x-arj-compressed"),
    MIME_ENTRY("rar", "application/x-rar-compressed"),
    MIME_ENTRY("rtf", "application/rtf"),
    MIME_ENTRY("pdf", "application/pdf"),
    MIME_ENTRY("swf", "application/x-shockwave-flash"),
    MIME_ENTRY("mpg", "video/mpeg"),
    MIME_ENTRY("webm", "video/webm"),
    MIME_ENTRY("mpeg", "video/mpeg"),
    MIME_ENTRY("mov", "video/quicktime"),
    MIME_ENTRY("mp4", "video/mp4"),
    MIME_ENTRY("m4v", "video/x-m4v"),
    MIME_ENTRY("asf", "video/x-ms-asf"),
    MIME_ENTRY("avi", "video/x-msvideo"),
    MIME_ENTRY("bmp", "image/bmp"),
    {NULL, 0, NULL} };

static struct mg_str mg_get_mime_type(const char *path, const char *dflt,
    const struct mg_serve_http_opts *opts) {
    const char *ext, *overrides;
    size_t i, path_len;
    struct mg_str r, k, v;

    path_len = strlen(path);

    overrides = opts->custom_mime_types;
    while ((overrides = mg_next_comma_list_entry(overrides, &k, &v)) != NULL) {
        ext = path + (path_len - k.len);
        if (path_len > k.len && mg_vcasecmp(&k, ext) == 0) {
            return v;
        }
    }

    for (i = 0; mg_static_builtin_mime_types[i].extension != NULL; i++) {
        ext = path + (path_len - mg_static_builtin_mime_types[i].ext_len);
        if (path_len > mg_static_builtin_mime_types[i].ext_len && ext[-1] == '.' &&
            mg_casecmp(ext, mg_static_builtin_mime_types[i].extension) == 0) {
            r.p = mg_static_builtin_mime_types[i].mime_type;
            r.len = strlen(r.p);
            return r;
        }
    }

    r.p = dflt;
    r.len = strlen(r.p);
    return r;
}
#endif

/*
 * Check whether full request is buffered. Return:
 *   -1  if request is malformed
 *    0  if request is not yet fully buffered
 *   >0  actual request length, including last \r\n\r\n
 */
static int mg_http_get_request_len(const char *s, int buf_len) {
    const unsigned char *buf = (unsigned char *)s;
    int i;

    for (i = 0; i < buf_len; i++) {
        if (!isprint(buf[i]) && buf[i] != '\r' && buf[i] != '\n' && buf[i] < 128) {
            return -1;
        }
        else if (buf[i] == '\n' && i + 1 < buf_len && buf[i + 1] == '\n') {
            return i + 2;
        }
        else if (buf[i] == '\n' && i + 2 < buf_len && buf[i + 1] == '\r' &&
            buf[i + 2] == '\n') {
            return i + 3;
        }
    }

    return 0;
}

static const char *mg_http_parse_headers(const char *s, const char *end,
    int len, struct http_message *req) {
    int i = 0;
    while (i < (int)ARRAY_SIZE(req->header_names) - 1) {
        struct mg_str *k = &req->header_names[i], *v = &req->header_values[i];

        s = mg_skip(s, end, ": ", k);
        s = mg_skip(s, end, "\r\n", v);

        while (v->len > 0 && v->p[v->len - 1] == ' ') {
            v->len--; /* Trim trailing spaces in header value */
        }

        /*
         * If header value is empty - skip it and go to next (if any).
         * NOTE: Do not add it to headers_values because such addition changes API
         * behaviour
         */
        if (k->len != 0 && v->len == 0) {
            continue;
        }

        if (k->len == 0 || v->len == 0) {
            k->p = v->p = NULL;
            k->len = v->len = 0;
            break;
        }

        if (!mg_ncasecmp(k->p, "Content-Length", 14)) {
            req->body.len = (size_t)to64(v->p);
            req->message.len = len + req->body.len;
        }

        i++;
    }

    return s;
}

int mg_parse_http(const char *s, int n, struct http_message *hm, int is_req) {
    const char *end, *qs;
    int len = mg_http_get_request_len(s, n);

    if (len <= 0) return len;

    memset(hm, 0, sizeof(*hm));
    hm->message.p = s;
    hm->body.p = s + len;
    hm->message.len = hm->body.len = (size_t)~0;
    end = s + len;

    /* Request is fully buffered. Skip leading whitespaces. */
    while (s < end && isspace(*(unsigned char *)s)) s++;

    if (is_req) {
        /* Parse request line: method, URI, proto */
        s = mg_skip(s, end, " ", &hm->method);
        s = mg_skip(s, end, " ", &hm->uri);
        s = mg_skip(s, end, "\r\n", &hm->proto);
        if (hm->uri.p <= hm->method.p || hm->proto.p <= hm->uri.p) return -1;

        /* If URI contains '?' character, initialize query_string */
        if ((qs = (char *)memchr(hm->uri.p, '?', hm->uri.len)) != NULL) {
            hm->query_string.p = qs + 1;
            hm->query_string.len = &hm->uri.p[hm->uri.len] - (qs + 1);
            hm->uri.len = qs - hm->uri.p;
        }
    }
    else {
        s = mg_skip(s, end, " ", &hm->proto);
        if (end - s < 4 || s[0] < '0' || s[0] > '9' || s[3] != ' ') return -1;
        hm->resp_code = atoi(s);
        if (hm->resp_code < 100 || hm->resp_code >= 600) return -1;
        s += 4;
        s = mg_skip(s, end, "\r\n", &hm->resp_status_msg);
    }

    s = mg_http_parse_headers(s, end, len, hm);

    /*
     * mg_parse_http() is used to parse both HTTP requests and HTTP
     * responses. If HTTP response does not have Content-Length set, then
     * body is read until socket is closed, i.e. body.len is infinite (~0).
     *
     * For HTTP requests though, according to
     * http://tools.ietf.org/html/rfc7231#section-8.1.3,
     * only POST and PUT methods have defined body semantics.
     * Therefore, if Content-Length is not specified and methods are
     * not one of PUT or POST, set body length to 0.
     *
     * So,
     * if it is HTTP request, and Content-Length is not set,
     * and method is not (PUT or POST) then reset body length to zero.
     */
    if (hm->body.len == (size_t)~0 && is_req &&
        mg_vcasecmp(&hm->method, "PUT") != 0 &&
        mg_vcasecmp(&hm->method, "POST") != 0) {
        hm->body.len = 0;
        hm->message.len = len;
    }

    return len;
}

struct mg_str *mg_get_http_header(struct http_message *hm, const char *name) {
    size_t i, len = strlen(name);

    for (i = 0; hm->header_names[i].len > 0; i++) {
        struct mg_str *h = &hm->header_names[i], *v = &hm->header_values[i];
        if (h->p != NULL && h->len == len && !mg_ncasecmp(h->p, name, len))
            return v;
    }

    return NULL;
}

#if MG_ENABLE_FILESYSTEM
static void mg_http_transfer_file_data(struct mg_connection *nc) {
    struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
    char buf[MG_MAX_HTTP_SEND_MBUF];
    size_t n = 0, to_read = 0, left = (size_t)(pd->file.cl - pd->file.sent);

    if (pd->file.type == DATA_FILE) {
        struct mbuf *io = &nc->send_mbuf;
        if (io->len >= MG_MAX_HTTP_SEND_MBUF) {
            to_read = 0;
        }
        else {
            to_read = MG_MAX_HTTP_SEND_MBUF - io->len;
        }
        if (to_read > left) {
            to_read = left;
        }
        if (to_read > 0) {
            n = mg_fread(buf, 1, to_read, pd->file.fp);
            if (n > 0) {
                mg_send(nc, buf, n);
                pd->file.sent += n;
                DBG(("%p sent %d (total %d)", nc, (int)n, (int)pd->file.sent));
            }
        }
        else {
            /* Rate-limited */
        }
        if (pd->file.sent >= pd->file.cl) {
            LOG(LL_DEBUG, ("%p done, %d bytes, ka %d", nc, (int)pd->file.sent,
                pd->file.keepalive));
            if (!pd->file.keepalive) nc->flags |= MG_F_SEND_AND_CLOSE;
            mg_http_free_proto_data_file(&pd->file);
        }
    }
    else if (pd->file.type == DATA_PUT) {
        struct mbuf *io = &nc->recv_mbuf;
        size_t to_write = left <= 0 ? 0 : left < io->len ? (size_t)left : io->len;
        size_t n = mg_fwrite(io->buf, 1, to_write, pd->file.fp);
        if (n > 0) {
            mbuf_remove(io, n);
            pd->file.sent += n;
        }
        if (n == 0 || pd->file.sent >= pd->file.cl) {
            if (!pd->file.keepalive) nc->flags |= MG_F_SEND_AND_CLOSE;
            mg_http_free_proto_data_file(&pd->file);
        }
    }
#if MG_ENABLE_HTTP_CGI
    else if (pd->cgi.cgi_nc != NULL) {
        /* This is POST data that needs to be forwarded to the CGI process */
        if (pd->cgi.cgi_nc != NULL) {
            mg_forward(nc, pd->cgi.cgi_nc);
        }
        else {
            nc->flags |= MG_F_SEND_AND_CLOSE;
        }
    }
#endif
}
#endif /* MG_ENABLE_FILESYSTEM */

/*
 * Parse chunked-encoded buffer. Return 0 if the buffer is not encoded, or
 * if it's incomplete. If the chunk is fully buffered, return total number of
 * bytes in a chunk, and store data in `data`, `data_len`.
 */
static size_t mg_http_parse_chunk(char *buf, size_t len, char **chunk_data,
    size_t *chunk_len) {
    unsigned char *s = (unsigned char *)buf;
    size_t n = 0; /* scanned chunk length */
    size_t i = 0; /* index in s */

    /* Scan chunk length. That should be a hexadecimal number. */
    while (i < len && isxdigit(s[i])) {
        n *= 16;
        n += (s[i] >= '0' && s[i] <= '9') ? s[i] - '0' : tolower(s[i]) - 'a' + 10;
        i++;
        if (i > 6) {
            /* Chunk size is unreasonable. */
            return 0;
        }
    }

    /* Skip new line */
    if (i == 0 || i + 2 > len || s[i] != '\r' || s[i + 1] != '\n') {
        return 0;
    }
    i += 2;

    /* Record where the data is */
    *chunk_data = (char *)s + i;
    *chunk_len = n;

    /* Skip data */
    i += n;

    /* Skip new line */
    if (i == 0 || i + 2 > len || s[i] != '\r' || s[i + 1] != '\n') {
        return 0;
    }
    return i + 2;
}

MG_INTERNAL size_t mg_handle_chunked(struct mg_connection *nc,
    struct http_message *hm, char *buf,
    size_t blen) {
    struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
    char *data;
    size_t i, n, data_len, body_len, zero_chunk_received = 0;
    /* Find out piece of received data that is not yet reassembled */
    body_len = (size_t)pd->chunk.body_len;
    assert(blen >= body_len);

    /* Traverse all fully buffered chunks */
    for (i = body_len;
        (n = mg_http_parse_chunk(buf + i, blen - i, &data, &data_len)) > 0;
        i += n) {
        /* Collapse chunk data to the rest of HTTP body */
        memmove(buf + body_len, data, data_len);
        body_len += data_len;
        hm->body.len = body_len;

        if (data_len == 0) {
            zero_chunk_received = 1;
            i += n;
            break;
        }
    }

    if (i > body_len) {
        /* Shift unparsed content to the parsed body */
        assert(i <= blen);
        memmove(buf + body_len, buf + i, blen - i);
        memset(buf + body_len + blen - i, 0, i - body_len);
        nc->recv_mbuf.len -= i - body_len;
        pd->chunk.body_len = body_len;

        /* Send MG_EV_HTTP_CHUNK event */
        nc->flags &= ~MG_F_DELETE_CHUNK;
        mg_call(nc, nc->handler, nc->user_data, MG_EV_HTTP_CHUNK, hm);

        /* Delete processed data if user set MG_F_DELETE_CHUNK flag */
        if (nc->flags & MG_F_DELETE_CHUNK) {
            memset(buf, 0, body_len);
            memmove(buf, buf + body_len, blen - i);
            nc->recv_mbuf.len -= body_len;
            hm->body.len = 0;
            pd->chunk.body_len = 0;
        }

        if (zero_chunk_received) {
            /* Total message size is len(body) + len(headers) */
            hm->message.len =
                (size_t)pd->chunk.body_len + blen - i + (hm->body.p - hm->message.p);
        }
    }

    return body_len;
}

struct mg_http_endpoint *mg_http_get_endpoint_handler(struct mg_connection *nc,
    struct mg_str *uri_path) {
    struct mg_http_proto_data *pd;
    struct mg_http_endpoint *ret = NULL;
    int matched, matched_max = 0;
    struct mg_http_endpoint *ep;

    if (nc == NULL) return NULL;

    pd = mg_http_get_proto_data(nc);

    if (pd == NULL) return NULL;

    ep = pd->endpoints;
    while (ep != NULL) {
        if ((matched = mg_match_prefix_n(ep->uri_pattern, *uri_path)) > 0) {
            if (matched > matched_max) {
                /* Looking for the longest suitable handler */
                ret = ep;
                matched_max = matched;
            }
        }

        ep = ep->next;
    }

    return ret;
}

#if MG_ENABLE_HTTP_STREAMING_MULTIPART
static void mg_http_multipart_continue(struct mg_connection *nc);

static void mg_http_multipart_begin(struct mg_connection *nc,
    struct http_message *hm, int req_len);

#endif

static void mg_http_call_endpoint_handler(struct mg_connection *nc, int ev,
    struct http_message *hm);

static void deliver_chunk(struct mg_connection *c, struct http_message *hm,
    int req_len) {
    /* Incomplete message received. Send MG_EV_HTTP_CHUNK event */
    hm->body.len = c->recv_mbuf.len - req_len;
    c->flags &= ~MG_F_DELETE_CHUNK;
    mg_call(c, c->handler, c->user_data, MG_EV_HTTP_CHUNK, hm);
    /* Delete processed data if user set MG_F_DELETE_CHUNK flag */
    if (c->flags & MG_F_DELETE_CHUNK) c->recv_mbuf.len = req_len;
}

/*
 * lx106 compiler has a bug (TODO(mkm) report and insert tracking bug here)
 * If a big structure is declared in a big function, lx106 gcc will make it
 * even bigger (round up to 4k, from 700 bytes of actual size).
 */
#ifdef __xtensa__
static void mg_http_handler2(struct mg_connection *nc, int ev,
    void *ev_data MG_UD_ARG(void *user_data),
    struct http_message *hm) __attribute__((noinline));

void mg_http_handler(struct mg_connection *nc, int ev,
    void *ev_data MG_UD_ARG(void *user_data)) {
    struct http_message hm;
    mg_http_handler2(nc, ev, ev_data MG_UD_ARG(user_data), &hm);
}

static void mg_http_handler2(struct mg_connection *nc, int ev,
    void *ev_data MG_UD_ARG(void *user_data),
    struct http_message *hm) {
#else  /* !__XTENSA__ */
void mg_http_handler(struct mg_connection *nc, int ev,
    void *ev_data MG_UD_ARG(void *user_data)) {
    struct http_message shm, *hm = &shm;
#endif /* __XTENSA__ */
    struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
    struct mbuf *io = &nc->recv_mbuf;
    int req_len;
    const int is_req = (nc->listener != NULL);
#if MG_ENABLE_HTTP_WEBSOCKET
    struct mg_str *vec;
#endif
    if (ev == MG_EV_CLOSE) {
#if MG_ENABLE_HTTP_CGI
        /* Close associated CGI forwarder connection */
        if (pd != NULL && pd->cgi.cgi_nc != NULL) {
            pd->cgi.cgi_nc->user_data = NULL;
            pd->cgi.cgi_nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        }
#endif
#if MG_ENABLE_HTTP_STREAMING_MULTIPART
        if (pd != NULL && pd->mp_stream.boundary != NULL) {
            /*
             * Multipart message is in progress, but connection is closed.
             * Finish part and request with an error flag.
             */
            struct mg_http_multipart_part mp;
            memset(&mp, 0, sizeof(mp));
            mp.status = -1;
            mp.user_data = pd->mp_stream.user_data;
            mp.var_name = pd->mp_stream.var_name;
            mp.file_name = pd->mp_stream.file_name;
            mg_call(nc, (pd->endpoint_handler ? pd->endpoint_handler : nc->handler),
                nc->user_data, MG_EV_HTTP_PART_END, &mp);
            mp.var_name = NULL;
            mp.file_name = NULL;
            mg_call(nc, (pd->endpoint_handler ? pd->endpoint_handler : nc->handler),
                nc->user_data, MG_EV_HTTP_MULTIPART_REQUEST_END, &mp);
        }
        else
#endif
            if (io->len > 0 &&
                (req_len = mg_parse_http(io->buf, io->len, hm, is_req)) > 0) {
                /*
                 * For HTTP messages without Content-Length, always send HTTP message
                 * before MG_EV_CLOSE message.
                 */
                int ev2 = is_req ? MG_EV_HTTP_REQUEST : MG_EV_HTTP_REPLY;
                hm->message.len = io->len;
                hm->body.len = io->buf + io->len - hm->body.p;
                deliver_chunk(nc, hm, req_len);
                mg_http_call_endpoint_handler(nc, ev2, hm);
            }
        if (pd != NULL && pd->endpoint_handler != NULL &&
            pd->endpoint_handler != nc->handler) {
            mg_call(nc, pd->endpoint_handler, nc->user_data, ev, NULL);
        }
    }

#if MG_ENABLE_FILESYSTEM
    if (pd != NULL && pd->file.fp != NULL) {
        mg_http_transfer_file_data(nc);
    }
#endif

    mg_call(nc, nc->handler, nc->user_data, ev, ev_data);

#if MG_ENABLE_HTTP_STREAMING_MULTIPART
    if (pd != NULL && pd->mp_stream.boundary != NULL &&
        (ev == MG_EV_RECV || ev == MG_EV_POLL)) {
        if (ev == MG_EV_RECV) {
            pd->rcvd += *(int *)ev_data;
            mg_http_multipart_continue(nc);
        }
        else if (pd->mp_stream.data_avail) {
            /* Try re-delivering the data. */
            mg_http_multipart_continue(nc);
        }
        return;
    }
#endif /* MG_ENABLE_HTTP_STREAMING_MULTIPART */

    if (ev == MG_EV_RECV) {
        struct mg_str *s;

    again:
        req_len = mg_parse_http(io->buf, io->len, hm, is_req);

        if (req_len > 0) {
            /* New request - new proto data */
            pd = mg_http_create_proto_data(nc);
            pd->rcvd = io->len;
        }

        if (req_len > 0 &&
            (s = mg_get_http_header(hm, "Transfer-Encoding")) != NULL &&
            mg_vcasecmp(s, "chunked") == 0) {
            mg_handle_chunked(nc, hm, io->buf + req_len, io->len - req_len);
        }

#if MG_ENABLE_HTTP_STREAMING_MULTIPART
        if (req_len > 0 && (s = mg_get_http_header(hm, "Content-Type")) != NULL &&
            s->len >= 9 && strncmp(s->p, "multipart", 9) == 0) {
            mg_http_multipart_begin(nc, hm, req_len);
            mg_http_multipart_continue(nc);
            return;
        }
#endif /* MG_ENABLE_HTTP_STREAMING_MULTIPART */

        /* TODO(alashkin): refactor this ifelseifelseifelseifelse */
        if ((req_len < 0 ||
            (req_len == 0 && io->len >= MG_MAX_HTTP_REQUEST_SIZE))) {
            DBG(("invalid request"));
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        }
        else if (req_len == 0) {
            /* Do nothing, request is not yet fully buffered */
        }
#if MG_ENABLE_HTTP_WEBSOCKET
        else if (nc->listener == NULL && (nc->flags & MG_F_IS_WEBSOCKET)) {
            /* We're websocket client, got handshake response from server. */
            DBG(("%p WebSocket upgrade code %d", nc, hm->resp_code));
            if (hm->resp_code == 101 &&
                mg_get_http_header(hm, "Sec-WebSocket-Accept")) {
                /* TODO(lsm): check the validity of accept Sec-WebSocket-Accept */
                mg_call(nc, nc->handler, nc->user_data, MG_EV_WEBSOCKET_HANDSHAKE_DONE,
                    hm);
                mbuf_remove(io, req_len);
                nc->proto_handler = mg_ws_handler;
                mg_ws_handler(nc, MG_EV_RECV, ev_data MG_UD_ARG(user_data));
            }
            else {
                mg_call(nc, nc->handler, nc->user_data, MG_EV_WEBSOCKET_HANDSHAKE_DONE,
                    hm);
                nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                mbuf_remove(io, req_len);
            }
        }
        else if (nc->listener != NULL &&
            (vec = mg_get_http_header(hm, "Sec-WebSocket-Key")) != NULL) {
            struct mg_http_endpoint *ep;

            /* This is a websocket request. Switch protocol handlers. */
            mbuf_remove(io, req_len);
            nc->proto_handler = mg_ws_handler;
            nc->flags |= MG_F_IS_WEBSOCKET;

            /*
             * If we have a handler set up with mg_register_http_endpoint(),
             * deliver subsequent websocket events to this handler after the
             * protocol switch.
             */
            ep = mg_http_get_endpoint_handler(nc->listener, &hm->uri);
            if (ep != NULL) {
                nc->handler = ep->handler;
#if MG_ENABLE_CALLBACK_USERDATA
                nc->user_data = ep->user_data;
#endif
            }

            /* Send handshake */
            mg_call(nc, nc->handler, nc->user_data, MG_EV_WEBSOCKET_HANDSHAKE_REQUEST,
                hm);
            if (!(nc->flags & (MG_F_CLOSE_IMMEDIATELY | MG_F_SEND_AND_CLOSE))) {
                if (nc->send_mbuf.len == 0) {
                    mg_ws_handshake(nc, vec, hm);
                }
                mg_call(nc, nc->handler, nc->user_data, MG_EV_WEBSOCKET_HANDSHAKE_DONE,
                    hm);
                mg_ws_handler(nc, MG_EV_RECV, ev_data MG_UD_ARG(user_data));
            }
        }
#endif /* MG_ENABLE_HTTP_WEBSOCKET */
        else if (hm->message.len > pd->rcvd) {
            /* Not yet received all HTTP body, deliver MG_EV_HTTP_CHUNK */
            deliver_chunk(nc, hm, req_len);
            if (nc->recv_mbuf_limit > 0 && nc->recv_mbuf.len >= nc->recv_mbuf_limit) {
                LOG(LL_ERROR, ("%p recv buffer (%lu bytes) exceeds the limit "
                    "%lu bytes, and not drained, closing",
                    nc, (unsigned long)nc->recv_mbuf.len,
                    (unsigned long)nc->recv_mbuf_limit));
                nc->flags |= MG_F_CLOSE_IMMEDIATELY;
            }
        }
        else {
            /* We did receive all HTTP body. */
            int request_done = 1;
            int trigger_ev = nc->listener ? MG_EV_HTTP_REQUEST : MG_EV_HTTP_REPLY;
            char addr[32];
            mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr),
                MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
            DBG(("%p %s %.*s %.*s", nc, addr, (int)hm->method.len, hm->method.p,
                (int)hm->uri.len, hm->uri.p));
            deliver_chunk(nc, hm, req_len);
            /* Whole HTTP message is fully buffered, call event handler */
            mg_http_call_endpoint_handler(nc, trigger_ev, hm);
            mbuf_remove(io, hm->message.len);
            pd->rcvd -= hm->message.len;
#if MG_ENABLE_FILESYSTEM
            /* We don't have a generic mechanism of communicating that we are done
             * responding to a request (should probably add one). But if we are
             * serving
             * a file, we are definitely not done. */
            if (pd->file.fp != NULL) request_done = 0;
#endif
#if MG_ENABLE_HTTP_CGI
            /* If this is a CGI request, we are not done either. */
            if (pd->cgi.cgi_nc != NULL) request_done = 0;
#endif
            if (request_done && io->len > 0) goto again;
        }
    }
}

static size_t mg_get_line_len(const char *buf, size_t buf_len) {
    size_t len = 0;
    while (len < buf_len && buf[len] != '\n') len++;
    return len == buf_len ? 0 : len + 1;
}

#if MG_ENABLE_HTTP_STREAMING_MULTIPART
static void mg_http_multipart_begin(struct mg_connection *nc,
    struct http_message *hm, int req_len) {
    struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
    struct mg_str *ct;
    struct mbuf *io = &nc->recv_mbuf;

    char boundary_buf[100];
    char *boundary = boundary_buf;
    int boundary_len;

    ct = mg_get_http_header(hm, "Content-Type");
    if (ct == NULL) {
        /* We need more data - or it isn't multipart mesage */
        goto exit_mp;
    }

    /* Content-type should start with "multipart" */
    if (ct->len < 9 || strncmp(ct->p, "multipart", 9) != 0) {
        goto exit_mp;
    }

    boundary_len =
        mg_http_parse_header2(ct, "boundary", &boundary, sizeof(boundary_buf));
    if (boundary_len == 0) {
        /*
         * Content type is multipart, but there is no boundary,
         * probably malformed request
         */
        nc->flags = MG_F_CLOSE_IMMEDIATELY;
        DBG(("invalid request"));
        goto exit_mp;
    }

    /* If we reach this place - that is multipart request */

    if (pd->mp_stream.boundary != NULL) {
        /*
         * Another streaming request was in progress,
         * looks like protocol error
         */
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
    }
    else {
        struct mg_http_endpoint *ep = NULL;
        pd->mp_stream.state = MPS_BEGIN;
        pd->mp_stream.boundary = strdup(boundary);
        pd->mp_stream.boundary_len = strlen(boundary);
        pd->mp_stream.var_name = pd->mp_stream.file_name = NULL;
        pd->endpoint_handler = nc->handler;

        ep = mg_http_get_endpoint_handler(nc->listener, &hm->uri);
        if (ep != NULL) {
            pd->endpoint_handler = ep->handler;
        }

        mg_http_call_endpoint_handler(nc, MG_EV_HTTP_MULTIPART_REQUEST, hm);

        mbuf_remove(io, req_len);
    }
exit_mp:
    if (boundary != boundary_buf) MG_FREE(boundary);
}

#define CONTENT_DISPOSITION "Content-Disposition: "

static size_t mg_http_multipart_call_handler(struct mg_connection *c, int ev,
    const char *data,
    size_t data_len) {
    struct mg_http_multipart_part mp;
    struct mg_http_proto_data *pd = mg_http_get_proto_data(c);
    memset(&mp, 0, sizeof(mp));

    mp.var_name = pd->mp_stream.var_name;
    mp.file_name = pd->mp_stream.file_name;
    mp.user_data = pd->mp_stream.user_data;
    mp.data.p = data;
    mp.data.len = data_len;
    mp.num_data_consumed = data_len;
    mg_call(c, pd->endpoint_handler, c->user_data, ev, &mp);
    pd->mp_stream.user_data = mp.user_data;
    pd->mp_stream.data_avail = (mp.num_data_consumed != data_len);
    return mp.num_data_consumed;
}

static int mg_http_multipart_finalize(struct mg_connection *c) {
    struct mg_http_proto_data *pd = mg_http_get_proto_data(c);

    mg_http_multipart_call_handler(c, MG_EV_HTTP_PART_END, NULL, 0);
    MG_FREE((void *)pd->mp_stream.file_name);
    pd->mp_stream.file_name = NULL;
    MG_FREE((void *)pd->mp_stream.var_name);
    pd->mp_stream.var_name = NULL;
    mg_http_multipart_call_handler(c, MG_EV_HTTP_MULTIPART_REQUEST_END, NULL, 0);
    mg_http_free_proto_data_mp_stream(&pd->mp_stream);
    pd->mp_stream.state = MPS_FINISHED;

    return 1;
}

static int mg_http_multipart_wait_for_boundary(struct mg_connection *c) {
    const char *boundary;
    struct mbuf *io = &c->recv_mbuf;
    struct mg_http_proto_data *pd = mg_http_get_proto_data(c);

    if (pd->mp_stream.boundary == NULL) {
        pd->mp_stream.state = MPS_FINALIZE;
        DBG(("Invalid request: boundary not initialized"));
        return 0;
    }

    if ((int)io->len < pd->mp_stream.boundary_len + 2) {
        return 0;
    }

    boundary = c_strnstr(io->buf, pd->mp_stream.boundary, io->len);
    if (boundary != NULL) {
        const char *boundary_end = (boundary + pd->mp_stream.boundary_len);
        if (io->len - (boundary_end - io->buf) < 4) {
            return 0;
        }
        if (strncmp(boundary_end, "--\r\n", 4) == 0) {
            pd->mp_stream.state = MPS_FINALIZE;
            mbuf_remove(io, (boundary_end - io->buf) + 4);
        }
        else {
            pd->mp_stream.state = MPS_GOT_BOUNDARY;
        }
    }
    else {
        return 0;
    }

    return 1;
}

static void mg_http_parse_header_internal(struct mg_str *hdr,
    const char *var_name,
    struct altbuf *ab);

static int mg_http_multipart_process_boundary(struct mg_connection *c) {
    int data_size;
    const char *boundary, *block_begin;
    struct mbuf *io = &c->recv_mbuf;
    struct mg_http_proto_data *pd = mg_http_get_proto_data(c);
    struct altbuf ab_file_name, ab_var_name;
    int line_len;
    boundary = c_strnstr(io->buf, pd->mp_stream.boundary, io->len);
    block_begin = boundary + pd->mp_stream.boundary_len + 2;
    data_size = io->len - (block_begin - io->buf);

    altbuf_init(&ab_file_name, NULL, 0);
    altbuf_init(&ab_var_name, NULL, 0);

    while (data_size > 0 &&
        (line_len = mg_get_line_len(block_begin, data_size)) != 0) {
        if (line_len > (int) sizeof(CONTENT_DISPOSITION) &&
            mg_ncasecmp(block_begin, CONTENT_DISPOSITION,
                sizeof(CONTENT_DISPOSITION) - 1) == 0) {
            struct mg_str header;

            header.p = block_begin + sizeof(CONTENT_DISPOSITION) - 1;
            header.len = line_len - sizeof(CONTENT_DISPOSITION) - 1;

            altbuf_reset(&ab_var_name);
            mg_http_parse_header_internal(&header, "name", &ab_var_name);

            altbuf_reset(&ab_file_name);
            mg_http_parse_header_internal(&header, "filename", &ab_file_name);

            block_begin += line_len;
            data_size -= line_len;

            continue;
        }

        if (line_len == 2 && mg_ncasecmp(block_begin, "\r\n", 2) == 0) {
            mbuf_remove(io, block_begin - io->buf + 2);

            if (pd->mp_stream.processing_part != 0) {
                mg_http_multipart_call_handler(c, MG_EV_HTTP_PART_END, NULL, 0);
            }

            /* Reserve 2 bytes for "\r\n" in file_name and var_name */
            altbuf_append(&ab_file_name, '\0');
            altbuf_append(&ab_file_name, '\0');
            altbuf_append(&ab_var_name, '\0');
            altbuf_append(&ab_var_name, '\0');

            MG_FREE((void *)pd->mp_stream.file_name);
            pd->mp_stream.file_name = altbuf_get_buf(&ab_file_name, 1 /* trim */);
            MG_FREE((void *)pd->mp_stream.var_name);
            pd->mp_stream.var_name = altbuf_get_buf(&ab_var_name, 1 /* trim */);

            mg_http_multipart_call_handler(c, MG_EV_HTTP_PART_BEGIN, NULL, 0);
            pd->mp_stream.state = MPS_WAITING_FOR_CHUNK;
            pd->mp_stream.processing_part++;
            return 1;
        }

        block_begin += line_len;
    }

    pd->mp_stream.state = MPS_WAITING_FOR_BOUNDARY;

    altbuf_reset(&ab_var_name);
    altbuf_reset(&ab_file_name);

    return 0;
}

static int mg_http_multipart_continue_wait_for_chunk(struct mg_connection *c) {
    struct mg_http_proto_data *pd = mg_http_get_proto_data(c);
    struct mbuf *io = &c->recv_mbuf;

    const char *boundary;
    if ((int)io->len < pd->mp_stream.boundary_len + 6 /* \r\n, --, -- */) {
        return 0;
    }

    boundary = c_strnstr(io->buf, pd->mp_stream.boundary, io->len);
    if (boundary == NULL) {
        int data_len = (io->len - (pd->mp_stream.boundary_len + 6));
        if (data_len > 0) {
            size_t consumed = mg_http_multipart_call_handler(
                c, MG_EV_HTTP_PART_DATA, io->buf, (size_t)data_len);
            mbuf_remove(io, consumed);
        }
        return 0;
    }
    else if (boundary != NULL) {
        size_t data_len = ((size_t)(boundary - io->buf) - 4);
        size_t consumed = mg_http_multipart_call_handler(c, MG_EV_HTTP_PART_DATA,
            io->buf, data_len);
        mbuf_remove(io, consumed);
        if (consumed == data_len) {
            mbuf_remove(io, 4);
            pd->mp_stream.state = MPS_WAITING_FOR_BOUNDARY;
            return 1;
        }
        else {
            return 0;
        }
    }
    else {
        return 0;
    }
}

static void mg_http_multipart_continue(struct mg_connection *c) {
    struct mg_http_proto_data *pd = mg_http_get_proto_data(c);
    while (1) {
        switch (pd->mp_stream.state) {
        case MPS_BEGIN: {
            pd->mp_stream.state = MPS_WAITING_FOR_BOUNDARY;
            break;
        }
        case MPS_WAITING_FOR_BOUNDARY: {
            if (mg_http_multipart_wait_for_boundary(c) == 0) {
                return;
            }
            break;
        }
        case MPS_GOT_BOUNDARY: {
            if (mg_http_multipart_process_boundary(c) == 0) {
                return;
            }
            break;
        }
        case MPS_WAITING_FOR_CHUNK: {
            if (mg_http_multipart_continue_wait_for_chunk(c) == 0) {
                return;
            }
            break;
        }
        case MPS_FINALIZE: {
            if (mg_http_multipart_finalize(c) == 0) {
                return;
            }
            break;
        }
        case MPS_FINISHED: {
            return;
        }
        }
    }
}

struct file_upload_state {
    char *lfn;
    size_t num_recd;
    FILE *fp;
};

#endif /* MG_ENABLE_HTTP_STREAMING_MULTIPART */

void mg_set_protocol_http_websocket(struct mg_connection *nc) {
    nc->proto_handler = mg_http_handler;
}

const char *mg_status_message(int status_code) {
    switch (status_code) {
    case 206:
        return "Partial Content";
    case 301:
        return "Moved";
    case 302:
        return "Found";
    case 400:
        return "Bad Request";
    case 401:
        return "Unauthorized";
    case 403:
        return "Forbidden";
    case 404:
        return "Not Found";
    case 416:
        return "Requested Range Not Satisfiable";
    case 418:
        return "I'm a teapot";
    case 500:
        return "Internal Server Error";
    case 502:
        return "Bad Gateway";
    case 503:
        return "Service Unavailable";

#if MG_ENABLE_EXTRA_ERRORS_DESC
    case 100:
        return "Continue";
    case 101:
        return "Switching Protocols";
    case 102:
        return "Processing";
    case 200:
        return "OK";
    case 201:
        return "Created";
    case 202:
        return "Accepted";
    case 203:
        return "Non-Authoritative Information";
    case 204:
        return "No Content";
    case 205:
        return "Reset Content";
    case 207:
        return "Multi-Status";
    case 208:
        return "Already Reported";
    case 226:
        return "IM Used";
    case 300:
        return "Multiple Choices";
    case 303:
        return "See Other";
    case 304:
        return "Not Modified";
    case 305:
        return "Use Proxy";
    case 306:
        return "Switch Proxy";
    case 307:
        return "Temporary Redirect";
    case 308:
        return "Permanent Redirect";
    case 402:
        return "Payment Required";
    case 405:
        return "Method Not Allowed";
    case 406:
        return "Not Acceptable";
    case 407:
        return "Proxy Authentication Required";
    case 408:
        return "Request Timeout";
    case 409:
        return "Conflict";
    case 410:
        return "Gone";
    case 411:
        return "Length Required";
    case 412:
        return "Precondition Failed";
    case 413:
        return "Payload Too Large";
    case 414:
        return "URI Too Long";
    case 415:
        return "Unsupported Media Type";
    case 417:
        return "Expectation Failed";
    case 422:
        return "Unprocessable Entity";
    case 423:
        return "Locked";
    case 424:
        return "Failed Dependency";
    case 426:
        return "Upgrade Required";
    case 428:
        return "Precondition Required";
    case 429:
        return "Too Many Requests";
    case 431:
        return "Request Header Fields Too Large";
    case 451:
        return "Unavailable For Legal Reasons";
    case 501:
        return "Not Implemented";
    case 504:
        return "Gateway Timeout";
    case 505:
        return "HTTP Version Not Supported";
    case 506:
        return "Variant Also Negotiates";
    case 507:
        return "Insufficient Storage";
    case 508:
        return "Loop Detected";
    case 510:
        return "Not Extended";
    case 511:
        return "Network Authentication Required";
#endif /* MG_ENABLE_EXTRA_ERRORS_DESC */

    default:
        return "OK";
    }
}

void mg_send_response_line_s(struct mg_connection *nc, int status_code,
    const struct mg_str extra_headers) {
    mg_printf(nc, "HTTP/1.1 %d %s\r\n", status_code,
        mg_status_message(status_code));
#ifndef MG_HIDE_SERVER_INFO
    mg_printf(nc, "Server: %s\r\n", mg_version_header);
#endif
    if (extra_headers.len > 0) {
        mg_printf(nc, "%.*s\r\n", (int)extra_headers.len, extra_headers.p);
    }
}

void mg_send_response_line(struct mg_connection *nc, int status_code,
    const char *extra_headers) {
    mg_send_response_line_s(nc, status_code, mg_mk_str(extra_headers));
}

void mg_http_send_redirect(struct mg_connection *nc, int status_code,
    const struct mg_str location,
    const struct mg_str extra_headers) {
    char bbody[100], *pbody = bbody;
    int bl = mg_asprintf(&pbody, sizeof(bbody),
        "<p>Moved <a href='%.*s'>here</a>.\r\n",
        (int)location.len, location.p);
    char bhead[150], *phead = bhead;
    mg_asprintf(&phead, sizeof(bhead),
        "Location: %.*s\r\n"
        "Content-Type: text/html\r\n"
        "Content-Length: %d\r\n"
        "Cache-Control: no-cache\r\n"
        "%.*s%s",
        (int)location.len, location.p, bl, (int)extra_headers.len,
        extra_headers.p, (extra_headers.len > 0 ? "\r\n" : ""));
    mg_send_response_line(nc, status_code, phead);
    if (phead != bhead) MG_FREE(phead);
    mg_send(nc, pbody, bl);
    if (pbody != bbody) MG_FREE(pbody);
}

void mg_send_head(struct mg_connection *c, int status_code,
    int64_t content_length, const char *extra_headers) {
    mg_send_response_line(c, status_code, extra_headers);
    if (content_length < 0) {
        mg_printf(c, "%s", "Transfer-Encoding: chunked\r\n");
    }
    else {
        mg_printf(c, "Content-Length: %" INT64_FMT "\r\n", content_length);
    }
    mg_send(c, "\r\n", 2);
}

void mg_http_send_error(struct mg_connection *nc, int code,
    const char *reason) {
    if (!reason) reason = mg_status_message(code);
    LOG(LL_DEBUG, ("%p %d %s", nc, code, reason));
    mg_send_head(nc, code, strlen(reason),
        "Content-Type: text/plain\r\nConnection: close");
    mg_send(nc, reason, strlen(reason));
    nc->flags |= MG_F_SEND_AND_CLOSE;
}

#if MG_ENABLE_FILESYSTEM
static void mg_http_construct_etag(char *buf, size_t buf_len,
    const cs_stat_t *st) {
    snprintf(buf, buf_len, "\"%lx.%" INT64_FMT "\"", (unsigned long)st->st_mtime,
        (int64_t)st->st_size);
}

#ifndef WINCE
static void mg_gmt_time_string(char *buf, size_t buf_len, time_t *t) {
    strftime(buf, buf_len, "%a, %d %b %Y %H:%M:%S GMT", gmtime(t));
}
#else
/* Look wince_lib.c for WindowsCE implementation */
static void mg_gmt_time_string(char *buf, size_t buf_len, time_t *t);
#endif

static int mg_http_parse_range_header(const struct mg_str *header, int64_t *a,
    int64_t *b) {
    /*
     * There is no snscanf. Headers are not guaranteed to be NUL-terminated,
     * so we have this. Ugh.
     */
    int result;
    char *p = (char *)MG_MALLOC(header->len + 1);
    if (p == NULL) return 0;
    memcpy(p, header->p, header->len);
    p[header->len] = '\0';
    result = sscanf(p, "bytes=%" INT64_FMT "-%" INT64_FMT, a, b);
    MG_FREE(p);
    return result;
}

void mg_http_serve_file(struct mg_connection *nc, struct http_message *hm,
    const char *path, const struct mg_str mime_type,
    const struct mg_str extra_headers) {
    struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
    cs_stat_t st;
    LOG(LL_DEBUG, ("%p [%s] %.*s", nc, path, (int)mime_type.len, mime_type.p));
    if (mg_stat(path, &st) != 0 || (pd->file.fp = mg_fopen(path, "rb")) == NULL) {
        int code, err = mg_get_errno();
        switch (err) {
        case EACCES:
            code = 403;
            break;
        case ENOENT:
            code = 404;
            break;
        default:
            code = 500;
        };
        mg_http_send_error(nc, code, "Open failed");
    }
    else {
        char etag[50], current_time[50], last_modified[50], range[70];
        time_t t = (time_t)mg_time();
        int64_t r1 = 0, r2 = 0, cl = st.st_size;
        struct mg_str *range_hdr = mg_get_http_header(hm, "Range");
        int n, status_code = 200;

        /* Handle Range header */
        range[0] = '\0';
        if (range_hdr != NULL &&
            (n = mg_http_parse_range_header(range_hdr, &r1, &r2)) > 0 && r1 >= 0 &&
            r2 >= 0) {
            /* If range is specified like "400-", set second limit to content len */
            if (n == 1) {
                r2 = cl - 1;
            }
            if (r1 > r2 || r2 >= cl) {
                status_code = 416;
                cl = 0;
                snprintf(range, sizeof(range),
                    "Content-Range: bytes */%" INT64_FMT "\r\n",
                    (int64_t)st.st_size);
            }
            else {
                status_code = 206;
                cl = r2 - r1 + 1;
                snprintf(range, sizeof(range), "Content-Range: bytes %" INT64_FMT
                    "-%" INT64_FMT "/%" INT64_FMT "\r\n",
                    r1, r1 + cl - 1, (int64_t)st.st_size);
#if _FILE_OFFSET_BITS == 64 || _POSIX_C_SOURCE >= 200112L || \
    _XOPEN_SOURCE >= 600
                fseeko(pd->file.fp, r1, SEEK_SET);
#else
                fseek(pd->file.fp, (long)r1, SEEK_SET);
#endif
            }
        }

#if !MG_DISABLE_HTTP_KEEP_ALIVE
        {
            struct mg_str *conn_hdr = mg_get_http_header(hm, "Connection");
            if (conn_hdr != NULL) {
                pd->file.keepalive = (mg_vcasecmp(conn_hdr, "keep-alive") == 0);
            }
            else {
                pd->file.keepalive = (mg_vcmp(&hm->proto, "HTTP/1.1") == 0);
            }
        }
#endif

        mg_http_construct_etag(etag, sizeof(etag), &st);
        mg_gmt_time_string(current_time, sizeof(current_time), &t);
        mg_gmt_time_string(last_modified, sizeof(last_modified), &st.st_mtime);
        /*
         * Content length casted to size_t because:
         * 1) that's the maximum buffer size anyway
         * 2) ESP8266 RTOS SDK newlib vprintf cannot contain a 64bit arg at non-last
         *    position
         * TODO(mkm): fix ESP8266 RTOS SDK
         */
        mg_send_response_line_s(nc, status_code, extra_headers);
        mg_printf(nc,
            "Date: %s\r\n"
            "Last-Modified: %s\r\n"
            "Accept-Ranges: bytes\r\n"
            "Content-Type: %.*s\r\n"
            "Connection: %s\r\n"
            "Content-Length: %" SIZE_T_FMT
            "\r\n"
            "%sEtag: %s\r\n\r\n",
            current_time, last_modified, (int)mime_type.len, mime_type.p,
            (pd->file.keepalive ? "keep-alive" : "close"), (size_t)cl, range,
            etag);

        pd->file.cl = cl;
        pd->file.type = DATA_FILE;
        mg_http_transfer_file_data(nc);
    }
}

static void mg_http_serve_file2(struct mg_connection *nc, const char *path,
    struct http_message *hm,
    struct mg_serve_http_opts *opts) {
#if MG_ENABLE_HTTP_SSI
    if (mg_match_prefix(opts->ssi_pattern, strlen(opts->ssi_pattern), path) > 0) {
        mg_handle_ssi_request(nc, hm, path, opts);
        return;
    }
#endif
    mg_http_serve_file(nc, hm, path, mg_get_mime_type(path, "text/plain", opts),
        mg_mk_str(opts->extra_headers));
}

#endif

int mg_url_decode(const char *src, int src_len, char *dst, int dst_len,
    int is_form_url_encoded) {
    int i, j, a, b;
#define HEXTOI(x) (isdigit(x) ? x - '0' : x - 'W')

    for (i = j = 0; i < src_len && j < dst_len - 1; i++, j++) {
        if (src[i] == '%') {
            if (i < src_len - 2 && isxdigit(*(const unsigned char *)(src + i + 1)) &&
                isxdigit(*(const unsigned char *)(src + i + 2))) {
                a = tolower(*(const unsigned char *)(src + i + 1));
                b = tolower(*(const unsigned char *)(src + i + 2));
                dst[j] = (char)((HEXTOI(a) << 4) | HEXTOI(b));
                i += 2;
            }
            else {
                return -1;
            }
        }
        else if (is_form_url_encoded && src[i] == '+') {
            dst[j] = ' ';
        }
        else {
            dst[j] = src[i];
        }
    }

    dst[j] = '\0'; /* Null-terminate the destination */

    return i >= src_len ? j : -1;
}

int mg_get_http_var(const struct mg_str *buf, const char *name, char *dst,
    size_t dst_len) {
    const char *p, *e, *s;
    size_t name_len;
    int len;

    /*
     * According to the documentation function returns negative
     * value in case of error. For debug purposes it returns:
     * -1 - src is wrong (NUUL)
     * -2 - dst is wrong (NULL)
     * -3 - failed to decode url or dst is to small
     * -4 - name does not exist
     */
    if (dst == NULL || dst_len == 0) {
        len = -2;
    }
    else if (buf->p == NULL || name == NULL || buf->len == 0) {
        len = -1;
        dst[0] = '\0';
    }
    else {
        name_len = strlen(name);
        e = buf->p + buf->len;
        len = -4;
        dst[0] = '\0';

        for (p = buf->p; p + name_len < e; p++) {
            if ((p == buf->p || p[-1] == '&') && p[name_len] == '=' &&
                !mg_ncasecmp(name, p, name_len)) {
                p += name_len + 1;
                s = (const char *)memchr(p, '&', (size_t)(e - p));
                if (s == NULL) {
                    s = e;
                }
                len = mg_url_decode(p, (size_t)(s - p), dst, dst_len, 1);
                /* -1 means: failed to decode or dst is too small */
                if (len == -1) {
                    len = -3;
                }
                break;
            }
        }
    }

    return len;
}

void mg_send_http_chunk(struct mg_connection *nc, const char *buf, size_t len) {
    char chunk_size[50];
    int n;

    n = snprintf(chunk_size, sizeof(chunk_size), "%lX\r\n", (unsigned long)len);
    mg_send(nc, chunk_size, n);
    mg_send(nc, buf, len);
    mg_send(nc, "\r\n", 2);
}

void mg_printf_http_chunk(struct mg_connection *nc, const char *fmt, ...) {
    char mem[MG_VPRINTF_BUFFER_SIZE], *buf = mem;
    int len;
    va_list ap;

    va_start(ap, fmt);
    len = mg_avprintf(&buf, sizeof(mem), fmt, ap);
    va_end(ap);

    if (len >= 0) {
        mg_send_http_chunk(nc, buf, len);
    }

    /* LCOV_EXCL_START */
    if (buf != mem && buf != NULL) {
        MG_FREE(buf);
    }
    /* LCOV_EXCL_STOP */
}

void mg_printf_html_escape(struct mg_connection *nc, const char *fmt, ...) {
    char mem[MG_VPRINTF_BUFFER_SIZE], *buf = mem;
    int i, j, len;
    va_list ap;

    va_start(ap, fmt);
    len = mg_avprintf(&buf, sizeof(mem), fmt, ap);
    va_end(ap);

    if (len >= 0) {
        for (i = j = 0; i < len; i++) {
            if (buf[i] == '<' || buf[i] == '>') {
                mg_send(nc, buf + j, i - j);
                mg_send(nc, buf[i] == '<' ? "&lt;" : "&gt;", 4);
                j = i + 1;
            }
        }
        mg_send(nc, buf + j, i - j);
    }

    /* LCOV_EXCL_START */
    if (buf != mem && buf != NULL) {
        MG_FREE(buf);
    }
    /* LCOV_EXCL_STOP */
}

static void mg_http_parse_header_internal(struct mg_str *hdr,
    const char *var_name,
    struct altbuf *ab) {
    int ch = ' ', ch1 = ',', ch2 = ';', n = strlen(var_name);
    const char *p, *end = hdr ? hdr->p + hdr->len : NULL, *s = NULL;

    /* Find where variable starts */
    for (s = hdr->p; s != NULL && s + n < end; s++) {
        if ((s == hdr->p || s[-1] == ch || s[-1] == ch1 || s[-1] == ';') &&
            s[n] == '=' && !strncmp(s, var_name, n))
            break;
    }

    if (s != NULL && &s[n + 1] < end) {
        s += n + 1;
        if (*s == '"' || *s == '\'') {
            ch = ch1 = ch2 = *s++;
        }
        p = s;
        while (p < end && p[0] != ch && p[0] != ch1 && p[0] != ch2) {
            if (ch != ' ' && p[0] == '\\' && p[1] == ch) p++;
            altbuf_append(ab, *p++);
        }

        if (ch != ' ' && *p != ch) {
            altbuf_reset(ab);
        }
    }

    /* If there is some data, append a NUL. */
    if (ab->len > 0) {
        altbuf_append(ab, '\0');
    }
}

int mg_http_parse_header2(struct mg_str *hdr, const char *var_name, char **buf,
    size_t buf_size) {
    struct altbuf ab;
    altbuf_init(&ab, *buf, buf_size);
    if (hdr == NULL) return 0;
    if (*buf != NULL && buf_size > 0) *buf[0] = '\0';

    mg_http_parse_header_internal(hdr, var_name, &ab);

    /*
     * Get a (trimmed) buffer, and return a len without a NUL byte which might
     * have been added.
     */
    *buf = altbuf_get_buf(&ab, 1 /* trim */);
    return ab.len > 0 ? ab.len - 1 : 0;
}

int mg_http_parse_header(struct mg_str *hdr, const char *var_name, char *buf,
    size_t buf_size) {
    char *buf2 = buf;

    int len = mg_http_parse_header2(hdr, var_name, &buf2, buf_size);

    if (buf2 != buf) {
        /* Buffer was not enough and was reallocated: free it and just return 0 */
        MG_FREE(buf2);
        return 0;
    }

    return len;
}

int mg_get_http_basic_auth(struct http_message *hm, char *user, size_t user_len,
    char *pass, size_t pass_len) {
    struct mg_str *hdr = mg_get_http_header(hm, "Authorization");
    if (hdr == NULL) return -1;
    return mg_parse_http_basic_auth(hdr, user, user_len, pass, pass_len);
}

int mg_parse_http_basic_auth(struct mg_str *hdr, char *user, size_t user_len,
    char *pass, size_t pass_len) {
    char *buf = NULL;
    char fmt[64];
    int res = 0;

    if (mg_strncmp(*hdr, mg_mk_str("Basic "), 6) != 0) return -1;

    buf = (char *)MG_MALLOC(hdr->len);
    cs_base64_decode((unsigned char *)hdr->p + 6, hdr->len, buf, NULL);

    /* e.g. "%123[^:]:%321[^\n]" */
    snprintf(fmt, sizeof(fmt), "%%%" SIZE_T_FMT "[^:]:%%%" SIZE_T_FMT "[^\n]",
        user_len - 1, pass_len - 1);
    if (sscanf(buf, fmt, user, pass) == 0) {
        res = -1;
    }

    MG_FREE(buf);
    return res;
}

#if MG_ENABLE_FILESYSTEM
static int mg_is_file_hidden(const char *path,
    const struct mg_serve_http_opts *opts,
    int exclude_specials) {
    const char *p1 = opts->per_directory_auth_file;
    const char *p2 = opts->hidden_file_pattern;

    /* Strip directory path from the file name */
    const char *pdir = strrchr(path, DIRSEP);
    if (pdir != NULL) {
        path = pdir + 1;
    }

    return (exclude_specials && (!strcmp(path, ".") || !strcmp(path, ".."))) ||
        (p1 != NULL && mg_match_prefix(p1, strlen(p1), path) == strlen(p1)) ||
        (p2 != NULL && mg_match_prefix(p2, strlen(p2), path) > 0);
}

#if !MG_DISABLE_HTTP_DIGEST_AUTH

#ifndef MG_EXT_MD5
void mg_hash_md5_v(size_t num_msgs, const uint8_t *msgs[],
    const size_t *msg_lens, uint8_t *digest) {
    size_t i;
    cs_md5_ctx md5_ctx;
    cs_md5_init(&md5_ctx);
    for (i = 0; i < num_msgs; i++) {
        cs_md5_update(&md5_ctx, msgs[i], msg_lens[i]);
    }
    cs_md5_final(digest, &md5_ctx);
}
#else
extern void mg_hash_md5_v(size_t num_msgs, const uint8_t *msgs[],
    const size_t *msg_lens, uint8_t *digest);
#endif

void cs_md5(char buf[33], ...) {
    unsigned char hash[16];
    const uint8_t *msgs[20], *p;
    size_t msg_lens[20];
    size_t num_msgs = 0;
    va_list ap;

    va_start(ap, buf);
    while ((p = va_arg(ap, const unsigned char *)) != NULL) {
        msgs[num_msgs] = p;
        msg_lens[num_msgs] = va_arg(ap, size_t);
        num_msgs++;
    }
    va_end(ap);

    mg_hash_md5_v(num_msgs, msgs, msg_lens, hash);
    cs_to_hex(buf, hash, sizeof(hash));
}

static void mg_mkmd5resp(const char *method, size_t method_len, const char *uri,
    size_t uri_len, const char *ha1, size_t ha1_len,
    const char *nonce, size_t nonce_len, const char *nc,
    size_t nc_len, const char *cnonce, size_t cnonce_len,
    const char *qop, size_t qop_len, char *resp) {
    static const char colon[] = ":";
    static const size_t one = 1;
    char ha2[33];
    cs_md5(ha2, method, method_len, colon, one, uri, uri_len, NULL);
    cs_md5(resp, ha1, ha1_len, colon, one, nonce, nonce_len, colon, one, nc,
        nc_len, colon, one, cnonce, cnonce_len, colon, one, qop, qop_len,
        colon, one, ha2, sizeof(ha2) - 1, NULL);
}

int mg_http_create_digest_auth_header(char *buf, size_t buf_len,
    const char *method, const char *uri,
    const char *auth_domain, const char *user,
    const char *passwd, const char *nonce) {
    static const char colon[] = ":", qop[] = "auth";
    static const size_t one = 1;
    char ha1[33], resp[33], cnonce[40];

    snprintf(cnonce, sizeof(cnonce), "%lx", (unsigned long)mg_time());
    cs_md5(ha1, user, (size_t)strlen(user), colon, one, auth_domain,
        (size_t)strlen(auth_domain), colon, one, passwd,
        (size_t)strlen(passwd), NULL);
    mg_mkmd5resp(method, strlen(method), uri, strlen(uri), ha1, sizeof(ha1) - 1,
        nonce, strlen(nonce), "1", one, cnonce, strlen(cnonce), qop,
        sizeof(qop) - 1, resp);
    return snprintf(buf, buf_len,
        "Authorization: Digest username=\"%s\","
        "realm=\"%s\",uri=\"%s\",qop=%s,nc=1,cnonce=%s,"
        "nonce=%s,response=%s\r\n",
        user, auth_domain, uri, qop, cnonce, nonce, resp);
}

/*
 * Check for authentication timeout.
 * Clients send time stamp encoded in nonce. Make sure it is not too old,
 * to prevent replay attacks.
 * Assumption: nonce is a hexadecimal number of seconds since 1970.
 */
static int mg_check_nonce(const char *nonce) {
    unsigned long now = (unsigned long)mg_time();
    unsigned long val = (unsigned long)strtoul(nonce, NULL, 16);
    return (now >= val) && (now - val < 60 * 60);
}

int mg_http_check_digest_auth(struct http_message *hm, const char *auth_domain,
    FILE *fp) {
    int ret = 0;
    struct mg_str *hdr;
    char username_buf[50], cnonce_buf[64], response_buf[40], uri_buf[200],
        qop_buf[20], nc_buf[20], nonce_buf[16];

    char *username = username_buf, *cnonce = cnonce_buf, *response = response_buf,
        *uri = uri_buf, *qop = qop_buf, *nc = nc_buf, *nonce = nonce_buf;

    /* Parse "Authorization:" header, fail fast on parse error */
    if (hm == NULL || fp == NULL ||
        (hdr = mg_get_http_header(hm, "Authorization")) == NULL ||
        mg_http_parse_header2(hdr, "username", &username, sizeof(username_buf)) ==
        0 ||
        mg_http_parse_header2(hdr, "cnonce", &cnonce, sizeof(cnonce_buf)) == 0 ||
        mg_http_parse_header2(hdr, "response", &response, sizeof(response_buf)) ==
        0 ||
        mg_http_parse_header2(hdr, "uri", &uri, sizeof(uri_buf)) == 0 ||
        mg_http_parse_header2(hdr, "qop", &qop, sizeof(qop_buf)) == 0 ||
        mg_http_parse_header2(hdr, "nc", &nc, sizeof(nc_buf)) == 0 ||
        mg_http_parse_header2(hdr, "nonce", &nonce, sizeof(nonce_buf)) == 0 ||
        mg_check_nonce(nonce) == 0) {
        ret = 0;
        goto clean;
    }

    /* NOTE(lsm): due to a bug in MSIE, we do not compare URIs */

    ret = mg_check_digest_auth(
        hm->method,
        mg_mk_str_n(
            hm->uri.p,
            hm->uri.len + (hm->query_string.len ? hm->query_string.len + 1 : 0)),
        mg_mk_str(username), mg_mk_str(cnonce), mg_mk_str(response),
        mg_mk_str(qop), mg_mk_str(nc), mg_mk_str(nonce), mg_mk_str(auth_domain),
        fp);

clean:
    if (username != username_buf) MG_FREE(username);
    if (cnonce != cnonce_buf) MG_FREE(cnonce);
    if (response != response_buf) MG_FREE(response);
    if (uri != uri_buf) MG_FREE(uri);
    if (qop != qop_buf) MG_FREE(qop);
    if (nc != nc_buf) MG_FREE(nc);
    if (nonce != nonce_buf) MG_FREE(nonce);

    return ret;
}

int mg_check_digest_auth(struct mg_str method, struct mg_str uri,
    struct mg_str username, struct mg_str cnonce,
    struct mg_str response, struct mg_str qop,
    struct mg_str nc, struct mg_str nonce,
    struct mg_str auth_domain, FILE *fp) {
    char buf[128], f_user[sizeof(buf)], f_ha1[sizeof(buf)], f_domain[sizeof(buf)];
    char exp_resp[33];

    /*
     * Read passwords file line by line. If should have htdigest format,
     * i.e. each line should be a colon-separated sequence:
     * USER_NAME:DOMAIN_NAME:HA1_HASH_OF_USER_DOMAIN_AND_PASSWORD
     */
    while (fgets(buf, sizeof(buf), fp) != NULL) {
        if (sscanf(buf, "%[^:]:%[^:]:%s", f_user, f_domain, f_ha1) == 3 &&
            mg_vcmp(&username, f_user) == 0 &&
            mg_vcmp(&auth_domain, f_domain) == 0) {
            /* Username and domain matched, check the password */
            mg_mkmd5resp(method.p, method.len, uri.p, uri.len, f_ha1, strlen(f_ha1),
                nonce.p, nonce.len, nc.p, nc.len, cnonce.p, cnonce.len,
                qop.p, qop.len, exp_resp);
            LOG(LL_DEBUG, ("%.*s %s %.*s %s", (int)username.len, username.p,
                f_domain, (int)response.len, response.p, exp_resp));
            return mg_ncasecmp(response.p, exp_resp, strlen(exp_resp)) == 0;
        }
    }

    /* None of the entries in the passwords file matched - return failure */
    return 0;
}

int mg_http_is_authorized(struct http_message *hm, struct mg_str path,
    const char *domain, const char *passwords_file,
    int flags) {
    char buf[MG_MAX_PATH];
    const char *p;
    FILE *fp;
    int authorized = 1;

    if (domain != NULL && passwords_file != NULL) {
        if (flags & MG_AUTH_FLAG_IS_GLOBAL_PASS_FILE) {
            fp = mg_fopen(passwords_file, "r");
        }
        else if (flags & MG_AUTH_FLAG_IS_DIRECTORY) {
            snprintf(buf, sizeof(buf), "%.*s%c%s", (int)path.len, path.p, DIRSEP,
                passwords_file);
            fp = mg_fopen(buf, "r");
        }
        else {
            p = strrchr(path.p, DIRSEP);
            if (p == NULL) p = path.p;
            snprintf(buf, sizeof(buf), "%.*s%c%s", (int)(p - path.p), path.p, DIRSEP,
                passwords_file);
            fp = mg_fopen(buf, "r");
        }

        if (fp != NULL) {
            authorized = mg_http_check_digest_auth(hm, domain, fp);
            fclose(fp);
        }
        else if (!(flags & MG_AUTH_FLAG_ALLOW_MISSING_FILE)) {
            authorized = 0;
        }
    }

    LOG(LL_DEBUG, ("%.*s %s %x %d", (int)path.len, path.p,
        passwords_file ? passwords_file : "", flags, authorized));
    return authorized;
}
#else
int mg_http_is_authorized(struct http_message *hm, const struct mg_str path,
    const char *domain, const char *passwords_file,
    int flags) {
    (void)hm;
    (void)path;
    (void)domain;
    (void)passwords_file;
    (void)flags;
    return 1;
}
#endif

#if MG_ENABLE_DIRECTORY_LISTING
static void mg_escape(const char *src, char *dst, size_t dst_len) {
    size_t n = 0;
    while (*src != '\0' && n + 5 < dst_len) {
        unsigned char ch = *(unsigned char *)src++;
        if (ch == '<') {
            n += snprintf(dst + n, dst_len - n, "%s", "&lt;");
        }
        else {
            dst[n++] = ch;
        }
    }
    dst[n] = '\0';
}

static void mg_print_dir_entry(struct mg_connection *nc, const char *file_name,
    cs_stat_t *stp) {
    char size[64], mod[64], path[MG_MAX_PATH];
    int64_t fsize = stp->st_size;
    int is_dir = S_ISDIR(stp->st_mode);
    const char *slash = is_dir ? "/" : "";
    struct mg_str href;

    if (is_dir) {
        snprintf(size, sizeof(size), "%s", "[DIRECTORY]");
    }
    else {
        /*
         * We use (double) cast below because MSVC 6 compiler cannot
         * convert unsigned __int64 to double.
         */
        if (fsize < 1024) {
            snprintf(size, sizeof(size), "%d", (int)fsize);
        }
        else if (fsize < 0x100000) {
            snprintf(size, sizeof(size), "%.1fk", (double)fsize / 1024.0);
        }
        else if (fsize < 0x40000000) {
            snprintf(size, sizeof(size), "%.1fM", (double)fsize / 1048576);
        }
        else {
            snprintf(size, sizeof(size), "%.1fG", (double)fsize / 1073741824);
        }
    }
    strftime(mod, sizeof(mod), "%d-%b-%Y %H:%M", localtime(&stp->st_mtime));
    mg_escape(file_name, path, sizeof(path));
    href = mg_url_encode(mg_mk_str(file_name));
    mg_printf_http_chunk(nc,
        "<tr><td><a href=\"%s%s\">%s%s</a></td>"
        "<td>%s</td><td name=%" INT64_FMT ">%s</td></tr>\n",
        href.p, slash, path, slash, mod, is_dir ? -1 : fsize,
        size);
    free((void *)href.p);
}

static void mg_scan_directory(struct mg_connection *nc, const char *dir,
    const struct mg_serve_http_opts *opts,
    void(*func)(struct mg_connection *, const char *,
        cs_stat_t *)) {
    char path[MG_MAX_PATH + 1];
    cs_stat_t st;
    struct dirent *dp;
    DIR *dirp;

    LOG(LL_DEBUG, ("%p [%s]", nc, dir));
    if ((dirp = (opendir(dir))) != NULL) {
        while ((dp = readdir(dirp)) != NULL) {
            /* Do not show current dir and hidden files */
            if (mg_is_file_hidden((const char *)dp->d_name, opts, 1)) {
                continue;
            }
            snprintf(path, sizeof(path), "%s/%s", dir, dp->d_name);
            if (mg_stat(path, &st) == 0) {
                func(nc, (const char *)dp->d_name, &st);
            }
        }
        closedir(dirp);
    }
    else {
        LOG(LL_DEBUG, ("%p opendir(%s) -> %d", nc, dir, mg_get_errno()));
    }
}

static void mg_send_directory_listing(struct mg_connection *nc, const char *dir,
    struct http_message *hm,
    struct mg_serve_http_opts *opts) {
    static const char *sort_js_code =
        "<script>function srt(tb, sc, so, d) {"
        "var tr = Array.prototype.slice.call(tb.rows, 0),"
        "tr = tr.sort(function (a, b) { var c1 = a.cells[sc], c2 = b.cells[sc],"
        "n1 = c1.getAttribute('name'), n2 = c2.getAttribute('name'), "
        "t1 = a.cells[2].getAttribute('name'), "
        "t2 = b.cells[2].getAttribute('name'); "
        "return so * (t1 < 0 && t2 >= 0 ? -1 : t2 < 0 && t1 >= 0 ? 1 : "
        "n1 ? parseInt(n2) - parseInt(n1) : "
        "c1.textContent.trim().localeCompare(c2.textContent.trim())); });";
    static const char *sort_js_code2 =
        "for (var i = 0; i < tr.length; i++) tb.appendChild(tr[i]); "
        "if (!d) window.location.hash = ('sc=' + sc + '&so=' + so); "
        "};"
        "window.onload = function() {"
        "var tb = document.getElementById('tb');"
        "var m = /sc=([012]).so=(1|-1)/.exec(window.location.hash) || [0, 2, 1];"
        "var sc = m[1], so = m[2]; document.onclick = function(ev) { "
        "var c = ev.target.rel; if (c) {if (c == sc) so *= -1; srt(tb, c, so); "
        "sc = c; ev.preventDefault();}};"
        "srt(tb, sc, so, true);"
        "}"
        "</script>";

    mg_send_response_line(nc, 200, opts->extra_headers);
    mg_printf(nc, "%s: %s\r\n%s: %s\r\n\r\n", "Transfer-Encoding", "chunked",
        "Content-Type", "text/html; charset=utf-8");

    mg_printf_http_chunk(
        nc,
        "<html><head><title>Index of %.*s</title>%s%s"
        "<style>th,td {text-align: left; padding-right: 1em; "
        "font-family: monospace; }</style></head>\n"
        "<body><h1>Index of %.*s</h1>\n<table cellpadding=0><thead>"
        "<tr><th><a href=# rel=0>Name</a></th><th>"
        "<a href=# rel=1>Modified</a</th>"
        "<th><a href=# rel=2>Size</a></th></tr>"
        "<tr><td colspan=3><hr></td></tr>\n"
        "</thead>\n"
        "<tbody id=tb>",
        (int)hm->uri.len, hm->uri.p, sort_js_code, sort_js_code2,
        (int)hm->uri.len, hm->uri.p);
    mg_scan_directory(nc, dir, opts, mg_print_dir_entry);
    mg_printf_http_chunk(nc,
        "</tbody><tr><td colspan=3><hr></td></tr>\n"
        "</table>\n"
        "<address>%s</address>\n"
        "</body></html>",
        mg_version_header);
    mg_send_http_chunk(nc, "", 0);
    /* TODO(rojer): Remove when cesanta/dev/issues/197 is fixed. */
    nc->flags |= MG_F_SEND_AND_CLOSE;
}
#endif /* MG_ENABLE_DIRECTORY_LISTING */

/*
 * Given a directory path, find one of the files specified in the
 * comma-separated list of index files `list`.
 * First found index file wins. If an index file is found, then gets
 * appended to the `path`, stat-ed, and result of `stat()` passed to `stp`.
 * If index file is not found, then `path` and `stp` remain unchanged.
 */
MG_INTERNAL void mg_find_index_file(const char *path, const char *list,
    char **index_file, cs_stat_t *stp) {
    struct mg_str vec;
    size_t path_len = strlen(path);
    int found = 0;
    *index_file = NULL;

    /* Traverse index files list. For each entry, append it to the given */
    /* path and see if the file exists. If it exists, break the loop */
    while ((list = mg_next_comma_list_entry(list, &vec, NULL)) != NULL) {
        cs_stat_t st;
        size_t len = path_len + 1 + vec.len + 1;
        *index_file = (char *)MG_REALLOC(*index_file, len);
        if (*index_file == NULL) break;
        snprintf(*index_file, len, "%s%c%.*s", path, DIRSEP, (int)vec.len, vec.p);

        /* Does it exist? Is it a file? */
        if (mg_stat(*index_file, &st) == 0 && S_ISREG(st.st_mode)) {
            /* Yes it does, break the loop */
            *stp = st;
            found = 1;
            break;
        }
    }
    if (!found) {
        MG_FREE(*index_file);
        *index_file = NULL;
    }
    LOG(LL_DEBUG, ("[%s] [%s]", path, (*index_file ? *index_file : "")));
}

#if MG_ENABLE_HTTP_URL_REWRITES
static int mg_http_send_port_based_redirect(
    struct mg_connection *c, struct http_message *hm,
    const struct mg_serve_http_opts *opts) {
    const char *rewrites = opts->url_rewrites;
    struct mg_str a, b;
    char local_port[20] = { '%' };

    mg_conn_addr_to_str(c, local_port + 1, sizeof(local_port) - 1,
        MG_SOCK_STRINGIFY_PORT);

    while ((rewrites = mg_next_comma_list_entry(rewrites, &a, &b)) != NULL) {
        if (mg_vcmp(&a, local_port) == 0) {
            mg_send_response_line(c, 301, NULL);
            mg_printf(c, "Content-Length: 0\r\nLocation: %.*s%.*s\r\n\r\n",
                (int)b.len, b.p, (int)(hm->proto.p - hm->uri.p - 1),
                hm->uri.p);
            return 1;
        }
    }

    return 0;
}

static void mg_reverse_proxy_handler(struct mg_connection *nc, int ev,
    void *ev_data MG_UD_ARG(void *user_data)) {
    struct http_message *hm = (struct http_message *) ev_data;
    struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);

    if (pd == NULL || pd->reverse_proxy_data.linked_conn == NULL) {
        DBG(("%p: upstream closed", nc));
        return;
    }

    switch (ev) {
    case MG_EV_CONNECT:
        if (*(int *)ev_data != 0) {
            mg_http_send_error(pd->reverse_proxy_data.linked_conn, 502, NULL);
        }
        break;
        /* TODO(mkm): handle streaming */
    case MG_EV_HTTP_REPLY:
        mg_send(pd->reverse_proxy_data.linked_conn, hm->message.p,
            hm->message.len);
        pd->reverse_proxy_data.linked_conn->flags |= MG_F_SEND_AND_CLOSE;
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        break;
    case MG_EV_CLOSE:
        pd->reverse_proxy_data.linked_conn->flags |= MG_F_SEND_AND_CLOSE;
        break;
    }

#if MG_ENABLE_CALLBACK_USERDATA
    (void) user_data;
#endif
}

void mg_http_reverse_proxy(struct mg_connection *nc,
    const struct http_message *hm, struct mg_str mount,
    struct mg_str upstream) {
    struct mg_connection *be;
    char burl[256], *purl = burl;
    int i;
    const char *error;
    struct mg_connect_opts opts;
    struct mg_str path = MG_NULL_STR, user_info = MG_NULL_STR, host = MG_NULL_STR;
    memset(&opts, 0, sizeof(opts));
    opts.error_string = &error;

    mg_asprintf(&purl, sizeof(burl), "%.*s%.*s", (int)upstream.len, upstream.p,
        (int)(hm->uri.len - mount.len), hm->uri.p + mount.len);

    be = mg_connect_http_base(nc->mgr, MG_CB(mg_reverse_proxy_handler, NULL),
        opts, "http", NULL, "https", NULL, purl, &path,
        &user_info, &host);
    LOG(LL_DEBUG, ("Proxying %.*s to %s (rule: %.*s)", (int)hm->uri.len,
        hm->uri.p, purl, (int)mount.len, mount.p));

    if (be == NULL) {
        LOG(LL_ERROR, ("Error connecting to %s: %s", purl, error));
        mg_http_send_error(nc, 502, NULL);
        goto cleanup;
    }

    /* link connections to each other, they must live and die together */
    mg_http_get_proto_data(be)->reverse_proxy_data.linked_conn = nc;
    mg_http_get_proto_data(nc)->reverse_proxy_data.linked_conn = be;

    /* send request upstream */
    mg_printf(be, "%.*s %.*s HTTP/1.1\r\n", (int)hm->method.len, hm->method.p,
        (int)path.len, path.p);

    mg_printf(be, "Host: %.*s\r\n", (int)host.len, host.p);
    for (i = 0; i < MG_MAX_HTTP_HEADERS && hm->header_names[i].len > 0; i++) {
        struct mg_str hn = hm->header_names[i];
        struct mg_str hv = hm->header_values[i];

        /* we rewrite the host header */
        if (mg_vcasecmp(&hn, "Host") == 0) continue;
        /*
         * Don't pass chunked transfer encoding to the client because hm->body is
         * already dechunked when we arrive here.
         */
        if (mg_vcasecmp(&hn, "Transfer-encoding") == 0 &&
            mg_vcasecmp(&hv, "chunked") == 0) {
            mg_printf(be, "Content-Length: %" SIZE_T_FMT "\r\n", hm->body.len);
            continue;
        }
        /* We don't support proxying Expect: 100-continue. */
        if (mg_vcasecmp(&hn, "Expect") == 0 &&
            mg_vcasecmp(&hv, "100-continue") == 0) {
            continue;
        }

        mg_printf(be, "%.*s: %.*s\r\n", (int)hn.len, hn.p, (int)hv.len, hv.p);
    }

    mg_send(be, "\r\n", 2);
    mg_send(be, hm->body.p, hm->body.len);

cleanup:
    if (purl != burl) MG_FREE(purl);
}

static int mg_http_handle_forwarding(struct mg_connection *nc,
    struct http_message *hm,
    const struct mg_serve_http_opts *opts) {
    const char *rewrites = opts->url_rewrites;
    struct mg_str a, b;
    struct mg_str p1 = MG_MK_STR("http://"), p2 = MG_MK_STR("https://");

    while ((rewrites = mg_next_comma_list_entry(rewrites, &a, &b)) != NULL) {
        if (mg_strncmp(a, hm->uri, a.len) == 0) {
            if (mg_strncmp(b, p1, p1.len) == 0 || mg_strncmp(b, p2, p2.len) == 0) {
                mg_http_reverse_proxy(nc, hm, a, b);
                return 1;
            }
        }
    }

    return 0;
}
#endif /* MG_ENABLE_FILESYSTEM */

MG_INTERNAL int mg_uri_to_local_path(struct http_message *hm,
    const struct mg_serve_http_opts *opts,
    char **local_path,
    struct mg_str *remainder) {
    int ok = 1;
    const char *cp = hm->uri.p, *cp_end = hm->uri.p + hm->uri.len;
    struct mg_str root = { NULL, 0 };
    const char *file_uri_start = cp;
    *local_path = NULL;
    remainder->p = NULL;
    remainder->len = 0;

    { /* 1. Determine which root to use. */

#if MG_ENABLE_HTTP_URL_REWRITES
        const char *rewrites = opts->url_rewrites;
#else
        const char *rewrites = "";
#endif
        struct mg_str *hh = mg_get_http_header(hm, "Host");
        struct mg_str a, b;
        /* Check rewrites first. */
        while ((rewrites = mg_next_comma_list_entry(rewrites, &a, &b)) != NULL) {
            if (a.len > 1 && a.p[0] == '@') {
                /* Host rewrite. */
                if (hh != NULL && hh->len == a.len - 1 &&
                    mg_ncasecmp(a.p + 1, hh->p, a.len - 1) == 0) {
                    root = b;
                    break;
                }
            }
            else {
                /* Regular rewrite, URI=directory */
                size_t match_len = mg_match_prefix_n(a, hm->uri);
                if (match_len > 0) {
                    file_uri_start = hm->uri.p + match_len;
                    if (*file_uri_start == '/' || file_uri_start == cp_end) {
                        /* Match ended at component boundary, ok. */
                    }
                    else if (*(file_uri_start - 1) == '/') {
                        /* Pattern ends with '/', backtrack. */
                        file_uri_start--;
                    }
                    else {
                        /* No match: must fall on the component boundary. */
                        continue;
                    }
                    root = b;
                    break;
                }
            }
        }
        /* If no rewrite rules matched, use DAV or regular document root. */
        if (root.p == NULL) {
#if MG_ENABLE_HTTP_WEBDAV
            if (opts->dav_document_root != NULL && mg_is_dav_request(&hm->method)) {
                root.p = opts->dav_document_root;
                root.len = strlen(opts->dav_document_root);
            }
            else
#endif
            {
                root.p = opts->document_root;
                root.len = strlen(opts->document_root);
            }
        }
        assert(root.p != NULL && root.len > 0);
    }

    { /* 2. Find where in the canonical URI path the local path ends. */
        const char *u = file_uri_start + 1;
        char *lp = (char *)MG_MALLOC(root.len + hm->uri.len + 1);
        char *lp_end = lp + root.len + hm->uri.len + 1;
        char *p = lp, *ps;
        int exists = 1;
        if (lp == NULL) {
            ok = 0;
            goto out;
        }
        memcpy(p, root.p, root.len);
        p += root.len;
        if (*(p - 1) == DIRSEP) p--;
        *p = '\0';
        ps = p;

        /* Chop off URI path components one by one and build local path. */
        while (u <= cp_end) {
            const char *next = u;
            struct mg_str component;
            if (exists) {
                cs_stat_t st;
                exists = (mg_stat(lp, &st) == 0);
                if (exists && S_ISREG(st.st_mode)) {
                    /* We found the terminal, the rest of the URI (if any) is path_info.
                     */
                    if (*(u - 1) == '/') u--;
                    break;
                }
            }
            if (u >= cp_end) break;
            parse_uri_component((const char **)&next, cp_end, "/", &component);
            if (component.len > 0) {
                int len;
                memmove(p + 1, component.p, component.len);
                len = mg_url_decode(p + 1, component.len, p + 1, lp_end - p - 1, 0);
                if (len <= 0) {
                    ok = 0;
                    break;
                }
                component.p = p + 1;
                component.len = len;
                if (mg_vcmp(&component, ".") == 0) {
                    /* Yum. */
                }
                else if (mg_vcmp(&component, "..") == 0) {
                    while (p > ps && *p != DIRSEP) p--;
                    *p = '\0';
                }
                else {
                    size_t i;
#ifdef _WIN32
                    /* On Windows, make sure it's valid Unicode (no funny stuff). */
                    wchar_t buf[MG_MAX_PATH * 2];
                    if (to_wchar(component.p, buf, MG_MAX_PATH) == 0) {
                        DBG(("[%.*s] smells funny", (int)component.len, component.p));
                        ok = 0;
                        break;
                    }
#endif
                    *p++ = DIRSEP;
                    /* No NULs and DIRSEPs in the component (percent-encoded). */
                    for (i = 0; i < component.len; i++, p++) {
                        if (*p == '\0' || *p == DIRSEP
#ifdef _WIN32
                            /* On Windows, "/" is also accepted, so check for that too. */
                            ||
                            *p == '/'
#endif
                            ) {
                            ok = 0;
                            break;
                        }
                    }
                }
            }
            u = next;
        }
        if (ok) {
            *local_path = lp;
            if (u > cp_end) u = cp_end;
            remainder->p = u;
            remainder->len = cp_end - u;
        }
        else {
            MG_FREE(lp);
        }
    }

out:
    LOG(LL_DEBUG,
        ("'%.*s' -> '%s' + '%.*s'", (int)hm->uri.len, hm->uri.p,
            *local_path ? *local_path : "", (int)remainder->len, remainder->p));
    return ok;
}

static int mg_get_month_index(const char *s) {
    static const char *month_names[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
                                        "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
    size_t i;

    for (i = 0; i < ARRAY_SIZE(month_names); i++)
        if (!strcmp(s, month_names[i])) return (int)i;

    return -1;
}

static int mg_num_leap_years(int year) {
    return year / 4 - year / 100 + year / 400;
}

/* Parse UTC date-time string, and return the corresponding time_t value. */
MG_INTERNAL time_t mg_parse_date_string(const char *datetime) {
    static const unsigned short days_before_month[] = {
        0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
    char month_str[32];
    int second, minute, hour, day, month, year, leap_days, days;
    time_t result = (time_t)0;

    if (((sscanf(datetime, "%d/%3s/%d %d:%d:%d", &day, month_str, &year, &hour,
        &minute, &second) == 6) ||
        (sscanf(datetime, "%d %3s %d %d:%d:%d", &day, month_str, &year, &hour,
            &minute, &second) == 6) ||
            (sscanf(datetime, "%*3s, %d %3s %d %d:%d:%d", &day, month_str, &year,
                &hour, &minute, &second) == 6) ||
                (sscanf(datetime, "%d-%3s-%d %d:%d:%d", &day, month_str, &year, &hour,
                    &minute, &second) == 6)) &&
        year > 1970 && (month = mg_get_month_index(month_str)) != -1) {
        leap_days = mg_num_leap_years(year) - mg_num_leap_years(1970);
        year -= 1970;
        days = year * 365 + days_before_month[month] + (day - 1) + leap_days;
        result = days * 24 * 3600 + hour * 3600 + minute * 60 + second;
    }

    return result;
}

MG_INTERNAL int mg_is_not_modified(struct http_message *hm, cs_stat_t *st) {
    struct mg_str *hdr;
    if ((hdr = mg_get_http_header(hm, "If-None-Match")) != NULL) {
        char etag[64];
        mg_http_construct_etag(etag, sizeof(etag), st);
        return mg_vcasecmp(hdr, etag) == 0;
    }
    else if ((hdr = mg_get_http_header(hm, "If-Modified-Since")) != NULL) {
        return st->st_mtime <= mg_parse_date_string(hdr->p);
    }
    else {
        return 0;
    }
}

void mg_http_send_digest_auth_request(struct mg_connection *c,
    const char *domain) {
    mg_printf(c,
        "HTTP/1.1 401 Unauthorized\r\n"
        "WWW-Authenticate: Digest qop=\"auth\", "
        "realm=\"%s\", nonce=\"%lx\"\r\n"
        "Content-Length: 0\r\n\r\n",
        domain, (unsigned long)mg_time());
}

static void mg_http_send_options(struct mg_connection *nc,
    struct mg_serve_http_opts *opts) {
    mg_send_response_line(nc, 200, opts->extra_headers);
    mg_printf(nc, "%s",
        "Allow: GET, POST, HEAD, CONNECT, OPTIONS"
#if MG_ENABLE_HTTP_WEBDAV
        ", MKCOL, PUT, DELETE, PROPFIND, MOVE\r\nDAV: 1,2"
#endif
        "\r\n\r\n");
    nc->flags |= MG_F_SEND_AND_CLOSE;
}

static int mg_is_creation_request(const struct http_message *hm) {
    return mg_vcmp(&hm->method, "MKCOL") == 0 || mg_vcmp(&hm->method, "PUT") == 0;
}

MG_INTERNAL void mg_send_http_file(struct mg_connection *nc, char *path,
    const struct mg_str *path_info,
    struct http_message *hm,
    struct mg_serve_http_opts *opts) {
    int exists, is_directory, is_cgi;
#if MG_ENABLE_HTTP_WEBDAV
    int is_dav = mg_is_dav_request(&hm->method);
#else
    int is_dav = 0;
#endif
    char *index_file = NULL;
    cs_stat_t st;

    exists = (mg_stat(path, &st) == 0);
    is_directory = exists && S_ISDIR(st.st_mode);

    if (is_directory)
        mg_find_index_file(path, opts->index_files, &index_file, &st);

    is_cgi =
        (mg_match_prefix(opts->cgi_file_pattern, strlen(opts->cgi_file_pattern),
            index_file ? index_file : path) > 0);

    LOG(LL_DEBUG,
        ("%p %.*s [%s] exists=%d is_dir=%d is_dav=%d is_cgi=%d index=%s", nc,
        (int)hm->method.len, hm->method.p, path, exists, is_directory, is_dav,
            is_cgi, index_file ? index_file : ""));

    if (is_directory && hm->uri.p[hm->uri.len - 1] != '/' && !is_dav) {
        mg_printf(nc,
            "HTTP/1.1 301 Moved\r\nLocation: %.*s/\r\n"
            "Content-Length: 0\r\n\r\n",
            (int)hm->uri.len, hm->uri.p);
        MG_FREE(index_file);
        return;
    }

    /* If we have path_info, the only way to handle it is CGI. */
    if (path_info->len > 0 && !is_cgi) {
        mg_http_send_error(nc, 501, NULL);
        MG_FREE(index_file);
        return;
    }

    if (is_dav && opts->dav_document_root == NULL) {
        mg_http_send_error(nc, 501, NULL);
    }
    else if (!mg_http_is_authorized(
        hm, mg_mk_str(path), opts->auth_domain, opts->global_auth_file,
        ((is_directory ? MG_AUTH_FLAG_IS_DIRECTORY : 0) |
            MG_AUTH_FLAG_IS_GLOBAL_PASS_FILE |
            MG_AUTH_FLAG_ALLOW_MISSING_FILE)) ||
        !mg_http_is_authorized(
            hm, mg_mk_str(path), opts->auth_domain,
            opts->per_directory_auth_file,
            ((is_directory ? MG_AUTH_FLAG_IS_DIRECTORY : 0) |
                MG_AUTH_FLAG_ALLOW_MISSING_FILE))) {
        mg_http_send_digest_auth_request(nc, opts->auth_domain);
    }
    else if (is_cgi) {
#if MG_ENABLE_HTTP_CGI
        mg_handle_cgi(nc, index_file ? index_file : path, path_info, hm, opts);
#else
        mg_http_send_error(nc, 501, NULL);
#endif /* MG_ENABLE_HTTP_CGI */
    }
    else if ((!exists ||
        mg_is_file_hidden(path, opts, 0 /* specials are ok */)) &&
        !mg_is_creation_request(hm)) {
        mg_http_send_error(nc, 404, NULL);
#if MG_ENABLE_HTTP_WEBDAV
    }
    else if (!mg_vcmp(&hm->method, "PROPFIND")) {
        mg_handle_propfind(nc, path, &st, hm, opts);
#if !MG_DISABLE_DAV_AUTH
    }
    else if (is_dav &&
        (opts->dav_auth_file == NULL ||
        (strcmp(opts->dav_auth_file, "-") != 0 &&
            !mg_http_is_authorized(
                hm, mg_mk_str(path), opts->auth_domain, opts->dav_auth_file,
                ((is_directory ? MG_AUTH_FLAG_IS_DIRECTORY : 0) |
                    MG_AUTH_FLAG_IS_GLOBAL_PASS_FILE |
                    MG_AUTH_FLAG_ALLOW_MISSING_FILE))))) {
        mg_http_send_digest_auth_request(nc, opts->auth_domain);
#endif
    }
    else if (!mg_vcmp(&hm->method, "MKCOL")) {
        mg_handle_mkcol(nc, path, hm);
    }
    else if (!mg_vcmp(&hm->method, "DELETE")) {
        mg_handle_delete(nc, opts, path);
    }
    else if (!mg_vcmp(&hm->method, "PUT")) {
        mg_handle_put(nc, path, hm);
    }
    else if (!mg_vcmp(&hm->method, "MOVE")) {
        mg_handle_move(nc, opts, path, hm);
#if MG_ENABLE_FAKE_DAVLOCK
    }
    else if (!mg_vcmp(&hm->method, "LOCK")) {
        mg_handle_lock(nc, path);
#endif
#endif /* MG_ENABLE_HTTP_WEBDAV */
    }
    else if (!mg_vcmp(&hm->method, "OPTIONS")) {
        mg_http_send_options(nc, opts);
    }
    else if (is_directory && index_file == NULL) {
#if MG_ENABLE_DIRECTORY_LISTING
        if (strcmp(opts->enable_directory_listing, "yes") == 0) {
            mg_send_directory_listing(nc, path, hm, opts);
        }
        else {
            mg_http_send_error(nc, 403, NULL);
        }
#else
        mg_http_send_error(nc, 501, NULL);
#endif
    }
    else if (mg_is_not_modified(hm, &st)) {
        mg_http_send_error(nc, 304, "Not Modified");
    }
    else {
        mg_http_serve_file2(nc, index_file ? index_file : path, hm, opts);
    }
    MG_FREE(index_file);
}

void mg_serve_http(struct mg_connection *nc, struct http_message *hm,
    struct mg_serve_http_opts opts) {
    char *path = NULL;
    struct mg_str *hdr, path_info;
    uint32_t remote_ip = ntohl(*(uint32_t *)&nc->sa.sin.sin_addr);

    if (mg_check_ip_acl(opts.ip_acl, remote_ip) != 1) {
        /* Not allowed to connect */
        mg_http_send_error(nc, 403, NULL);
        nc->flags |= MG_F_SEND_AND_CLOSE;
        return;
    }

#if MG_ENABLE_HTTP_URL_REWRITES
    if (mg_http_handle_forwarding(nc, hm, &opts)) {
        return;
    }

    if (mg_http_send_port_based_redirect(nc, hm, &opts)) {
        return;
    }
#endif

    if (opts.document_root == NULL) {
        opts.document_root = ".";
    }
    if (opts.per_directory_auth_file == NULL) {
        opts.per_directory_auth_file = ".htpasswd";
    }
    if (opts.enable_directory_listing == NULL) {
        opts.enable_directory_listing = "yes";
    }
    if (opts.cgi_file_pattern == NULL) {
        opts.cgi_file_pattern = "**.cgi$|**.php$";
    }
    if (opts.ssi_pattern == NULL) {
        opts.ssi_pattern = "**.shtml$|**.shtm$";
    }
    if (opts.index_files == NULL) {
        opts.index_files = "index.html,index.htm,index.shtml,index.cgi,index.php";
    }
    /* Normalize path - resolve "." and ".." (in-place). */
    if (!mg_normalize_uri_path(&hm->uri, &hm->uri)) {
        mg_http_send_error(nc, 400, NULL);
        return;
    }
    if (mg_uri_to_local_path(hm, &opts, &path, &path_info) == 0) {
        mg_http_send_error(nc, 404, NULL);
        return;
    }
    mg_send_http_file(nc, path, &path_info, hm, &opts);

    MG_FREE(path);
    path = NULL;

    /* Close connection for non-keep-alive requests */
    if (mg_vcmp(&hm->proto, "HTTP/1.1") != 0 ||
        ((hdr = mg_get_http_header(hm, "Connection")) != NULL &&
            mg_vcmp(hdr, "keep-alive") != 0)) {
#if 0
        nc->flags |= MG_F_SEND_AND_CLOSE;
#endif
    }
}

#if MG_ENABLE_HTTP_STREAMING_MULTIPART
void mg_file_upload_handler(struct mg_connection *nc, int ev, void *ev_data,
    mg_fu_fname_fn local_name_fn
    MG_UD_ARG(void *user_data)) {
    switch (ev) {
    case MG_EV_HTTP_PART_BEGIN: {
        struct mg_http_multipart_part *mp =
            (struct mg_http_multipart_part *) ev_data;
        struct file_upload_state *fus;
        struct mg_str lfn = local_name_fn(nc, mg_mk_str(mp->file_name));
        mp->user_data = NULL;
        if (lfn.p == NULL || lfn.len == 0) {
            LOG(LL_ERROR, ("%p Not allowed to upload %s", nc, mp->file_name));
            mg_printf(nc,
                "HTTP/1.1 403 Not Allowed\r\n"
                "Content-Type: text/plain\r\n"
                "Connection: close\r\n\r\n"
                "Not allowed to upload %s\r\n",
                mp->file_name);
            nc->flags |= MG_F_SEND_AND_CLOSE;
            return;
        }
        fus = (struct file_upload_state *) MG_CALLOC(1, sizeof(*fus));
        if (fus == NULL) {
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
            return;
        }
        fus->lfn = (char *)MG_MALLOC(lfn.len + 1);
        memcpy(fus->lfn, lfn.p, lfn.len);
        fus->lfn[lfn.len] = '\0';
        if (lfn.p != mp->file_name) MG_FREE((char *)lfn.p);
        LOG(LL_DEBUG,
            ("%p Receiving file %s -> %s", nc, mp->file_name, fus->lfn));
        fus->fp = mg_fopen(fus->lfn, "wb");
        if (fus->fp == NULL) {
            mg_printf(nc,
                "HTTP/1.1 500 Internal Server Error\r\n"
                "Content-Type: text/plain\r\n"
                "Connection: close\r\n\r\n");
            LOG(LL_ERROR, ("Failed to open %s: %d\n", fus->lfn, mg_get_errno()));
            mg_printf(nc, "Failed to open %s: %d\n", fus->lfn, mg_get_errno());
            /* Do not close the connection just yet, discard remainder of the data.
             * This is because at the time of writing some browsers (Chrome) fail to
             * render response before all the data is sent. */
        }
        mp->user_data = (void *)fus;
        break;
    }
    case MG_EV_HTTP_PART_DATA: {
        struct mg_http_multipart_part *mp =
            (struct mg_http_multipart_part *) ev_data;
        struct file_upload_state *fus =
            (struct file_upload_state *) mp->user_data;
        if (fus == NULL || fus->fp == NULL) break;
        if (mg_fwrite(mp->data.p, 1, mp->data.len, fus->fp) != mp->data.len) {
            LOG(LL_ERROR, ("Failed to write to %s: %d, wrote %d", fus->lfn,
                mg_get_errno(), (int)fus->num_recd));
            if (mg_get_errno() == ENOSPC
#ifdef SPIFFS_ERR_FULL
                || mg_get_errno() == SPIFFS_ERR_FULL
#endif
                ) {
                mg_printf(nc,
                    "HTTP/1.1 413 Payload Too Large\r\n"
                    "Content-Type: text/plain\r\n"
                    "Connection: close\r\n\r\n");
                mg_printf(nc, "Failed to write to %s: no space left; wrote %d\r\n",
                    fus->lfn, (int)fus->num_recd);
            }
            else {
                mg_printf(nc,
                    "HTTP/1.1 500 Internal Server Error\r\n"
                    "Content-Type: text/plain\r\n"
                    "Connection: close\r\n\r\n");
                mg_printf(nc, "Failed to write to %s: %d, wrote %d", mp->file_name,
                    mg_get_errno(), (int)fus->num_recd);
            }
            fclose(fus->fp);
            remove(fus->lfn);
            fus->fp = NULL;
            /* Do not close the connection just yet, discard remainder of the data.
             * This is because at the time of writing some browsers (Chrome) fail to
             * render response before all the data is sent. */
            return;
        }
        fus->num_recd += mp->data.len;
        LOG(LL_DEBUG, ("%p rec'd %d bytes, %d total", nc, (int)mp->data.len,
            (int)fus->num_recd));
        break;
    }
    case MG_EV_HTTP_PART_END: {
        struct mg_http_multipart_part *mp =
            (struct mg_http_multipart_part *) ev_data;
        struct file_upload_state *fus =
            (struct file_upload_state *) mp->user_data;
        if (fus == NULL) break;
        if (mp->status >= 0 && fus->fp != NULL) {
            LOG(LL_DEBUG, ("%p Uploaded %s (%s), %d bytes", nc, mp->file_name,
                fus->lfn, (int)fus->num_recd));
        }
        else {
            LOG(LL_ERROR, ("Failed to store %s (%s)", mp->file_name, fus->lfn));
            /*
             * mp->status < 0 means connection was terminated, so no reason to send
             * HTTP reply
             */
        }
        if (fus->fp != NULL) fclose(fus->fp);
        MG_FREE(fus->lfn);
        MG_FREE(fus);
        mp->user_data = NULL;
        /* Don't close the connection yet, there may be more files to come. */
        break;
    }
    case MG_EV_HTTP_MULTIPART_REQUEST_END: {
        mg_printf(nc,
            "HTTP/1.1 200 OK\r\n"
            "Content-Type: text/plain\r\n"
            "Connection: close\r\n\r\n"
            "Ok.\r\n");
        nc->flags |= MG_F_SEND_AND_CLOSE;
        break;
    }
    }

#if MG_ENABLE_CALLBACK_USERDATA
    (void) user_data;
#endif
}

#endif /* MG_ENABLE_HTTP_STREAMING_MULTIPART */
#endif /* MG_ENABLE_FILESYSTEM */

struct mg_connection *mg_connect_http_base(
    struct mg_mgr *mgr, MG_CB(mg_event_handler_t ev_handler, void *user_data),
    struct mg_connect_opts opts, const char *scheme1, const char *scheme2,
    const char *scheme_ssl1, const char *scheme_ssl2, const char *url,
    struct mg_str *path, struct mg_str *user_info, struct mg_str *host) {
    struct mg_connection *nc = NULL;
    unsigned int port_i = 0;
    int use_ssl = 0;
    struct mg_str scheme, query, fragment;
    char conn_addr_buf[2];
    char *conn_addr = conn_addr_buf;

    if (mg_parse_uri(mg_mk_str(url), &scheme, user_info, host, &port_i, path,
        &query, &fragment) != 0) {
        MG_SET_PTRPTR(opts.error_string, "cannot parse url");
        goto out;
    }

    /* If query is present, do not strip it. Pass to the caller. */
    if (query.len > 0) path->len += query.len + 1;

    if (scheme.len == 0 || mg_vcmp(&scheme, scheme1) == 0 ||
        (scheme2 != NULL && mg_vcmp(&scheme, scheme2) == 0)) {
        use_ssl = 0;
        if (port_i == 0) port_i = 80;
    }
    else if (mg_vcmp(&scheme, scheme_ssl1) == 0 ||
        (scheme2 != NULL && mg_vcmp(&scheme, scheme_ssl2) == 0)) {
        use_ssl = 1;
        if (port_i == 0) port_i = 443;
    }
    else {
        goto out;
    }

    mg_asprintf(&conn_addr, sizeof(conn_addr_buf), "tcp://%.*s:%u",
        (int)host->len, host->p, port_i);
    if (conn_addr == NULL) goto out;

    LOG(LL_DEBUG, ("%s use_ssl? %d %s", url, use_ssl, conn_addr));
    if (use_ssl) {
#if MG_ENABLE_SSL
        /*
         * Schema requires SSL, but no SSL parameters were provided in opts.
         * In order to maintain backward compatibility, use a faux-SSL with no
         * verification.
         */
        if (opts.ssl_ca_cert == NULL) {
            opts.ssl_ca_cert = "*";
        }
#else
        MG_SET_PTRPTR(opts.error_string, "ssl is disabled");
        goto out;
#endif
    }

    if ((nc = mg_connect_opt(mgr, conn_addr, MG_CB(ev_handler, user_data),
        opts)) != NULL) {
        mg_set_protocol_http_websocket(nc);
    }

out:
    if (conn_addr != NULL && conn_addr != conn_addr_buf) MG_FREE(conn_addr);
    return nc;
}

struct mg_connection *mg_connect_http_opt(
    struct mg_mgr *mgr, MG_CB(mg_event_handler_t ev_handler, void *user_data),
    struct mg_connect_opts opts, const char *url, const char *extra_headers,
    const char *post_data) {
    struct mg_str user = MG_NULL_STR, null_str = MG_NULL_STR;
    struct mg_str host = MG_NULL_STR, path = MG_NULL_STR;
    struct mbuf auth;
    struct mg_connection *nc =
        mg_connect_http_base(mgr, MG_CB(ev_handler, user_data), opts, "http",
            NULL, "https", NULL, url, &path, &user, &host);

    if (nc == NULL) {
        return NULL;
    }

    mbuf_init(&auth, 0);
    if (user.len > 0) {
        mg_basic_auth_header(user, null_str, &auth);
    }

    if (post_data == NULL) post_data = "";
    if (extra_headers == NULL) extra_headers = "";
    if (path.len == 0) path = mg_mk_str("/");
    if (host.len == 0) host = mg_mk_str("");

    mg_printf(nc, "%s %.*s HTTP/1.1\r\nHost: %.*s\r\nContent-Length: %" SIZE_T_FMT
        "\r\n%.*s%s\r\n%s",
        (post_data[0] == '\0' ? "GET" : "POST"), (int)path.len, path.p,
        (int)(path.p - host.p), host.p, strlen(post_data), (int)auth.len,
        (auth.buf == NULL ? "" : auth.buf), extra_headers, post_data);

    mbuf_free(&auth);
    return nc;
}

struct mg_connection *mg_connect_http(
    struct mg_mgr *mgr, MG_CB(mg_event_handler_t ev_handler, void *user_data),
    const char *url, const char *extra_headers, const char *post_data) {
    struct mg_connect_opts opts;
    memset(&opts, 0, sizeof(opts));
    return mg_connect_http_opt(mgr, MG_CB(ev_handler, user_data), opts, url,
        extra_headers, post_data);
}

size_t mg_parse_multipart(const char *buf, size_t buf_len, char *var_name,
    size_t var_name_len, char *file_name,
    size_t file_name_len, const char **data,
    size_t *data_len) {
    static const char cd[] = "Content-Disposition: ";
    size_t hl, bl, n, ll, pos, cdl = sizeof(cd) - 1;
    int shl;

    if (buf == NULL || buf_len <= 0) return 0;
    if ((shl = mg_http_get_request_len(buf, buf_len)) <= 0) return 0;
    hl = shl;
    if (buf[0] != '-' || buf[1] != '-' || buf[2] == '\n') return 0;

    /* Get boundary length */
    bl = mg_get_line_len(buf, buf_len);

    /* Loop through headers, fetch variable name and file name */
    var_name[0] = file_name[0] = '\0';
    for (n = bl; (ll = mg_get_line_len(buf + n, hl - n)) > 0; n += ll) {
        if (mg_ncasecmp(cd, buf + n, cdl) == 0) {
            struct mg_str header;
            header.p = buf + n + cdl;
            header.len = ll - (cdl + 2);
            {
                char *var_name2 = var_name;
                mg_http_parse_header2(&header, "name", &var_name2, var_name_len);
                /* TODO: handle reallocated buffer correctly */
                if (var_name2 != var_name) {
                    MG_FREE(var_name2);
                    var_name[0] = '\0';
                }
            }
            {
                char *file_name2 = file_name;
                mg_http_parse_header2(&header, "filename", &file_name2, file_name_len);
                /* TODO: handle reallocated buffer correctly */
                if (file_name2 != file_name) {
                    MG_FREE(file_name2);
                    file_name[0] = '\0';
                }
            }
        }
    }

    /* Scan through the body, search for terminating boundary */
    for (pos = hl; pos + (bl - 2) < buf_len; pos++) {
        if (buf[pos] == '-' && !strncmp(buf, &buf[pos], bl - 2)) {
            if (data_len != NULL) *data_len = (pos - 2) - hl;
            if (data != NULL) *data = buf + hl;
            return pos;
        }
    }

    return 0;
}

void mg_register_http_endpoint_opt(struct mg_connection *nc,
    const char *uri_path,
    mg_event_handler_t handler,
    struct mg_http_endpoint_opts opts) {
    struct mg_http_proto_data *pd = NULL;
    struct mg_http_endpoint *new_ep = NULL;

    if (nc == NULL) return;
    new_ep = (struct mg_http_endpoint *) MG_CALLOC(1, sizeof(*new_ep));
    if (new_ep == NULL) return;

    pd = mg_http_get_proto_data(nc);
    if (pd == NULL) pd = mg_http_create_proto_data(nc);
    new_ep->uri_pattern = mg_strdup(mg_mk_str(uri_path));
    if (opts.auth_domain != NULL && opts.auth_file != NULL) {
        new_ep->auth_domain = strdup(opts.auth_domain);
        new_ep->auth_file = strdup(opts.auth_file);
    }
    new_ep->handler = handler;
#if MG_ENABLE_CALLBACK_USERDATA
    new_ep->user_data = opts.user_data;
#endif
    new_ep->next = pd->endpoints;
    pd->endpoints = new_ep;
}

static void mg_http_call_endpoint_handler(struct mg_connection *nc, int ev,
    struct http_message *hm) {
    struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
    void *user_data = nc->user_data;

    if (ev == MG_EV_HTTP_REQUEST
#if MG_ENABLE_HTTP_STREAMING_MULTIPART
        || ev == MG_EV_HTTP_MULTIPART_REQUEST
#endif
        ) {
        struct mg_http_endpoint *ep =
            mg_http_get_endpoint_handler(nc->listener, &hm->uri);
        if (ep != NULL) {
#if MG_ENABLE_FILESYSTEM && !MG_DISABLE_HTTP_DIGEST_AUTH
            if (!mg_http_is_authorized(hm, hm->uri, ep->auth_domain, ep->auth_file,
                MG_AUTH_FLAG_IS_GLOBAL_PASS_FILE)) {
                mg_http_send_digest_auth_request(nc, ep->auth_domain);
                return;
            }
#endif
            pd->endpoint_handler = ep->handler;
#if MG_ENABLE_CALLBACK_USERDATA
            user_data = ep->user_data;
#endif
        }
    }
    mg_call(nc, pd->endpoint_handler ? pd->endpoint_handler : nc->handler,
        user_data, ev, hm);
}

void mg_register_http_endpoint(struct mg_connection *nc, const char *uri_path,
    MG_CB(mg_event_handler_t handler,
        void *user_data)) {
    struct mg_http_endpoint_opts opts;
    memset(&opts, 0, sizeof(opts));
#if MG_ENABLE_CALLBACK_USERDATA
    opts.user_data = user_data;
#endif
    mg_register_http_endpoint_opt(nc, uri_path, handler, opts);
}

#endif /* MG_ENABLE_HTTP */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_http_cgi.c"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

#ifndef _WIN32
#include <signal.h>
#endif

#if MG_ENABLE_HTTP && MG_ENABLE_HTTP_CGI

#ifndef MG_MAX_CGI_ENVIR_VARS
#define MG_MAX_CGI_ENVIR_VARS 64
#endif

#ifndef MG_ENV_EXPORT_TO_CGI
#define MG_ENV_EXPORT_TO_CGI "MONGOOSE_CGI"
#endif

#define MG_F_HTTP_CGI_PARSE_HEADERS MG_F_USER_1

 /*
  * This structure helps to create an environment for the spawned CGI program.
  * Environment is an array of "VARIABLE=VALUE\0" ASCIIZ strings,
  * last element must be NULL.
  * However, on Windows there is a requirement that all these VARIABLE=VALUE\0
  * strings must reside in a contiguous buffer. The end of the buffer is
  * marked by two '\0' characters.
  * We satisfy both worlds: we create an envp array (which is vars), all
  * entries are actually pointers inside buf.
  */
struct mg_cgi_env_block {
    struct mg_connection *nc;
    char buf[MG_CGI_ENVIRONMENT_SIZE];       /* Environment buffer */
    const char *vars[MG_MAX_CGI_ENVIR_VARS]; /* char *envp[] */
    int len;                                 /* Space taken */
    int nvars;                               /* Number of variables in envp[] */
};

#ifdef _WIN32
struct mg_threadparam {
    sock_t s;
    HANDLE hPipe;
};

static int mg_wait_until_ready(sock_t sock, int for_read) {
    fd_set set;
    FD_ZERO(&set);
    FD_SET(sock, &set);
    return select(sock + 1, for_read ? &set : 0, for_read ? 0 : &set, 0, 0) == 1;
}

static void *mg_push_to_stdin(void *arg) {
    struct mg_threadparam *tp = (struct mg_threadparam *) arg;
    int n, sent, stop = 0;
    DWORD k;
    char buf[BUFSIZ];

    while (!stop && mg_wait_until_ready(tp->s, 1) &&
        (n = recv(tp->s, buf, sizeof(buf), 0)) > 0) {
        if (n == -1 && GetLastError() == WSAEWOULDBLOCK) continue;
        for (sent = 0; !stop && sent < n; sent += k) {
            if (!WriteFile(tp->hPipe, buf + sent, n - sent, &k, 0)) stop = 1;
        }
    }
    DBG(("%s", "FORWARED EVERYTHING TO CGI"));
    CloseHandle(tp->hPipe);
    MG_FREE(tp);
    return NULL;
}

static void *mg_pull_from_stdout(void *arg) {
    struct mg_threadparam *tp = (struct mg_threadparam *) arg;
    int k = 0, stop = 0;
    DWORD n, sent;
    char buf[BUFSIZ];

    while (!stop && ReadFile(tp->hPipe, buf, sizeof(buf), &n, NULL)) {
        for (sent = 0; !stop && sent < n; sent += k) {
            if (mg_wait_until_ready(tp->s, 0) &&
                (k = send(tp->s, buf + sent, n - sent, 0)) <= 0)
                stop = 1;
        }
    }
    DBG(("%s", "EOF FROM CGI"));
    CloseHandle(tp->hPipe);
    shutdown(tp->s, 2);  // Without this, IO thread may get truncated data
    closesocket(tp->s);
    MG_FREE(tp);
    return NULL;
}

static void mg_spawn_stdio_thread(sock_t sock, HANDLE hPipe,
    void *(*func)(void *)) {
    struct mg_threadparam *tp = (struct mg_threadparam *) MG_MALLOC(sizeof(*tp));
    if (tp != NULL) {
        tp->s = sock;
        tp->hPipe = hPipe;
        mg_start_thread(func, tp);
    }
}

static void mg_abs_path(const char *utf8_path, char *abs_path, size_t len) {
    wchar_t buf[MG_MAX_PATH], buf2[MG_MAX_PATH];
    to_wchar(utf8_path, buf, ARRAY_SIZE(buf));
    GetFullPathNameW(buf, ARRAY_SIZE(buf2), buf2, NULL);
    WideCharToMultiByte(CP_UTF8, 0, buf2, wcslen(buf2) + 1, abs_path, len, 0, 0);
}

static int mg_start_process(const char *interp, const char *cmd,
    const char *env, const char *envp[],
    const char *dir, sock_t sock) {
    STARTUPINFOW si;
    PROCESS_INFORMATION pi;
    HANDLE a[2], b[2], me = GetCurrentProcess();
    wchar_t wcmd[MG_MAX_PATH], full_dir[MG_MAX_PATH];
    char buf[MG_MAX_PATH], buf2[MG_MAX_PATH], buf5[MG_MAX_PATH],
        buf4[MG_MAX_PATH], cmdline[MG_MAX_PATH];
    DWORD flags = DUPLICATE_CLOSE_SOURCE | DUPLICATE_SAME_ACCESS;
    FILE *fp;

    memset(&si, 0, sizeof(si));
    memset(&pi, 0, sizeof(pi));

    si.cb = sizeof(si);
    si.dwFlags = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW;
    si.wShowWindow = SW_HIDE;
    si.hStdError = GetStdHandle(STD_ERROR_HANDLE);

    CreatePipe(&a[0], &a[1], NULL, 0);
    CreatePipe(&b[0], &b[1], NULL, 0);
    DuplicateHandle(me, a[0], me, &si.hStdInput, 0, TRUE, flags);
    DuplicateHandle(me, b[1], me, &si.hStdOutput, 0, TRUE, flags);

    if (interp == NULL && (fp = mg_fopen(cmd, "r")) != NULL) {
        buf[0] = buf[1] = '\0';
        fgets(buf, sizeof(buf), fp);
        buf[sizeof(buf) - 1] = '\0';
        if (buf[0] == '#' && buf[1] == '!') {
            interp = buf + 2;
            /* Trim leading spaces: https://github.com/cesanta/mongoose/issues/489 */
            while (*interp != '\0' && isspace(*(unsigned char *)interp)) {
                interp++;
            }
        }
        fclose(fp);
    }

    snprintf(buf, sizeof(buf), "%s/%s", dir, cmd);
    mg_abs_path(buf, buf2, ARRAY_SIZE(buf2));

    mg_abs_path(dir, buf5, ARRAY_SIZE(buf5));
    to_wchar(dir, full_dir, ARRAY_SIZE(full_dir));

    if (interp != NULL) {
        mg_abs_path(interp, buf4, ARRAY_SIZE(buf4));
        snprintf(cmdline, sizeof(cmdline), "%s \"%s\"", buf4, buf2);
    }
    else {
        snprintf(cmdline, sizeof(cmdline), "\"%s\"", buf2);
    }
    to_wchar(cmdline, wcmd, ARRAY_SIZE(wcmd));

    if (CreateProcessW(NULL, wcmd, NULL, NULL, TRUE, CREATE_NEW_PROCESS_GROUP,
        (void *)env, full_dir, &si, &pi) != 0) {
        mg_spawn_stdio_thread(sock, a[1], mg_push_to_stdin);
        mg_spawn_stdio_thread(sock, b[0], mg_pull_from_stdout);

        CloseHandle(si.hStdOutput);
        CloseHandle(si.hStdInput);

        CloseHandle(pi.hThread);
        CloseHandle(pi.hProcess);
    }
    else {
        CloseHandle(a[1]);
        CloseHandle(b[0]);
        closesocket(sock);
    }
    DBG(("CGI command: [%ls] -> %p", wcmd, pi.hProcess));

    /* Not closing a[0] and b[1] because we've used DUPLICATE_CLOSE_SOURCE */
    (void)envp;
    return (pi.hProcess != NULL);
}
#else
static int mg_start_process(const char *interp, const char *cmd,
    const char *env, const char *envp[],
    const char *dir, sock_t sock) {
    char buf[500];
    pid_t pid = fork();
    (void)env;

    if (pid == 0) {
        /*
         * In Linux `chdir` declared with `warn_unused_result` attribute
         * To shutup compiler we have yo use result in some way
         */
        int tmp = chdir(dir);
        (void)tmp;
        (void)dup2(sock, 0);
        (void)dup2(sock, 1);
        closesocket(sock);

        /*
         * After exec, all signal handlers are restored to their default values,
         * with one exception of SIGCHLD. According to POSIX.1-2001 and Linux's
         * implementation, SIGCHLD's handler will leave unchanged after exec
         * if it was set to be ignored. Restore it to default action.
         */
        signal(SIGCHLD, SIG_DFL);

        if (interp == NULL) {
            execle(cmd, cmd, (char *)0, envp); /* (char *) 0 to squash warning */
        }
        else {
            execle(interp, interp, cmd, (char *)0, envp);
        }
        snprintf(buf, sizeof(buf),
            "Status: 500\r\n\r\n"
            "500 Server Error: %s%s%s: %s",
            interp == NULL ? "" : interp, interp == NULL ? "" : " ", cmd,
            strerror(errno));
        send(1, buf, strlen(buf), 0);
        _exit(EXIT_FAILURE); /* exec call failed */
    }

    return (pid != 0);
}
#endif /* _WIN32 */

/*
 * Append VARIABLE=VALUE\0 string to the buffer, and add a respective
 * pointer into the vars array.
 */
static char *mg_addenv(struct mg_cgi_env_block *block, const char *fmt, ...) {
    int n, space;
    char *added = block->buf + block->len;
    va_list ap;

    /* Calculate how much space is left in the buffer */
    space = sizeof(block->buf) - (block->len + 2);
    if (space > 0) {
        /* Copy VARIABLE=VALUE\0 string into the free space */
        va_start(ap, fmt);
        n = vsnprintf(added, (size_t)space, fmt, ap);
        va_end(ap);

        /* Make sure we do not overflow buffer and the envp array */
        if (n > 0 && n + 1 < space &&
            block->nvars < (int)ARRAY_SIZE(block->vars) - 2) {
            /* Append a pointer to the added string into the envp array */
            block->vars[block->nvars++] = added;
            /* Bump up used length counter. Include \0 terminator */
            block->len += n + 1;
        }
    }

    return added;
}

static void mg_addenv2(struct mg_cgi_env_block *blk, const char *name) {
    const char *s;
    if ((s = getenv(name)) != NULL) mg_addenv(blk, "%s=%s", name, s);
}

static void mg_prepare_cgi_environment(struct mg_connection *nc,
    const char *prog,
    const struct mg_str *path_info,
    const struct http_message *hm,
    const struct mg_serve_http_opts *opts,
    struct mg_cgi_env_block *blk) {
    const char *s;
    struct mg_str *h;
    char *p;
    size_t i;
    char buf[100];
    size_t path_info_len = path_info != NULL ? path_info->len : 0;

    blk->len = blk->nvars = 0;
    blk->nc = nc;

    if ((s = getenv("SERVER_NAME")) != NULL) {
        mg_addenv(blk, "SERVER_NAME=%s", s);
    }
    else {
        mg_sock_to_str(nc->sock, buf, sizeof(buf), 3);
        mg_addenv(blk, "SERVER_NAME=%s", buf);
    }
    mg_addenv(blk, "SERVER_ROOT=%s", opts->document_root);
    mg_addenv(blk, "DOCUMENT_ROOT=%s", opts->document_root);
    mg_addenv(blk, "SERVER_SOFTWARE=%s/%s", "Mongoose", MG_VERSION);

    /* Prepare the environment block */
    mg_addenv(blk, "%s", "GATEWAY_INTERFACE=CGI/1.1");
    mg_addenv(blk, "%s", "SERVER_PROTOCOL=HTTP/1.1");
    mg_addenv(blk, "%s", "REDIRECT_STATUS=200"); /* For PHP */

    mg_addenv(blk, "REQUEST_METHOD=%.*s", (int)hm->method.len, hm->method.p);

    mg_addenv(blk, "REQUEST_URI=%.*s%s%.*s", (int)hm->uri.len, hm->uri.p,
        hm->query_string.len == 0 ? "" : "?", (int)hm->query_string.len,
        hm->query_string.p);

    mg_conn_addr_to_str(nc, buf, sizeof(buf),
        MG_SOCK_STRINGIFY_REMOTE | MG_SOCK_STRINGIFY_IP);
    mg_addenv(blk, "REMOTE_ADDR=%s", buf);
    mg_conn_addr_to_str(nc, buf, sizeof(buf), MG_SOCK_STRINGIFY_PORT);
    mg_addenv(blk, "SERVER_PORT=%s", buf);

    s = hm->uri.p + hm->uri.len - path_info_len - 1;
    if (*s == '/') {
        const char *base_name = strrchr(prog, DIRSEP);
        mg_addenv(blk, "SCRIPT_NAME=%.*s/%s", (int)(s - hm->uri.p), hm->uri.p,
            (base_name != NULL ? base_name + 1 : prog));
    }
    else {
        mg_addenv(blk, "SCRIPT_NAME=%.*s", (int)(s - hm->uri.p + 1), hm->uri.p);
    }
    mg_addenv(blk, "SCRIPT_FILENAME=%s", prog);

    if (path_info != NULL && path_info->len > 0) {
        mg_addenv(blk, "PATH_INFO=%.*s", (int)path_info->len, path_info->p);
        /* Not really translated... */
        mg_addenv(blk, "PATH_TRANSLATED=%.*s", (int)path_info->len, path_info->p);
    }

#if MG_ENABLE_SSL
    mg_addenv(blk, "HTTPS=%s", (nc->flags & MG_F_SSL ? "on" : "off"));
#else
    mg_addenv(blk, "HTTPS=off");
#endif

    if ((h = mg_get_http_header((struct http_message *) hm, "Content-Type")) !=
        NULL) {
        mg_addenv(blk, "CONTENT_TYPE=%.*s", (int)h->len, h->p);
    }

    if (hm->query_string.len > 0) {
        mg_addenv(blk, "QUERY_STRING=%.*s", (int)hm->query_string.len,
            hm->query_string.p);
    }

    if ((h = mg_get_http_header((struct http_message *) hm, "Content-Length")) !=
        NULL) {
        mg_addenv(blk, "CONTENT_LENGTH=%.*s", (int)h->len, h->p);
    }

    mg_addenv2(blk, "PATH");
    mg_addenv2(blk, "TMP");
    mg_addenv2(blk, "TEMP");
    mg_addenv2(blk, "TMPDIR");
    mg_addenv2(blk, "PERLLIB");
    mg_addenv2(blk, MG_ENV_EXPORT_TO_CGI);

#ifdef _WIN32
    mg_addenv2(blk, "COMSPEC");
    mg_addenv2(blk, "SYSTEMROOT");
    mg_addenv2(blk, "SystemDrive");
    mg_addenv2(blk, "ProgramFiles");
    mg_addenv2(blk, "ProgramFiles(x86)");
    mg_addenv2(blk, "CommonProgramFiles(x86)");
#else
    mg_addenv2(blk, "LD_LIBRARY_PATH");
#endif /* _WIN32 */

    /* Add all headers as HTTP_* variables */
    for (i = 0; hm->header_names[i].len > 0; i++) {
        p = mg_addenv(blk, "HTTP_%.*s=%.*s", (int)hm->header_names[i].len,
            hm->header_names[i].p, (int)hm->header_values[i].len,
            hm->header_values[i].p);

        /* Convert variable name into uppercase, and change - to _ */
        for (; *p != '=' && *p != '\0'; p++) {
            if (*p == '-') *p = '_';
            *p = (char)toupper(*(unsigned char *)p);
        }
    }

    blk->vars[blk->nvars++] = NULL;
    blk->buf[blk->len++] = '\0';
}

static void mg_cgi_ev_handler(struct mg_connection *cgi_nc, int ev,
    void *ev_data MG_UD_ARG(void *user_data)) {
#if !MG_ENABLE_CALLBACK_USERDATA
    void *user_data = cgi_nc->user_data;
#endif
    struct mg_connection *nc = (struct mg_connection *) user_data;
    (void)ev_data;

    if (nc == NULL) {
        /* The corresponding network connection was closed. */
        cgi_nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        return;
    }

    switch (ev) {
    case MG_EV_RECV:
        /*
         * CGI script does not output reply line, like "HTTP/1.1 CODE XXXXX\n"
         * It outputs headers, then body. Headers might include "Status"
         * header, which changes CODE, and it might include "Location" header
         * which changes CODE to 302.
         *
         * Therefore we do not send the output from the CGI script to the user
         * until all CGI headers are received.
         *
         * Here we parse the output from the CGI script, and if all headers has
         * been received, send appropriate reply line, and forward all
         * received headers to the client.
         */
        if (nc->flags & MG_F_HTTP_CGI_PARSE_HEADERS) {
            struct mbuf *io = &cgi_nc->recv_mbuf;
            int len = mg_http_get_request_len(io->buf, io->len);

            if (len == 0) break;
            if (len < 0 || io->len > MG_MAX_HTTP_REQUEST_SIZE) {
                cgi_nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                mg_http_send_error(nc, 500, "Bad headers");
            }
            else {
                struct http_message hm;
                struct mg_str *h;
                mg_http_parse_headers(io->buf, io->buf + io->len, io->len, &hm);
                if (mg_get_http_header(&hm, "Location") != NULL) {
                    mg_printf(nc, "%s", "HTTP/1.1 302 Moved\r\n");
                }
                else if ((h = mg_get_http_header(&hm, "Status")) != NULL) {
                    mg_printf(nc, "HTTP/1.1 %.*s\r\n", (int)h->len, h->p);
                }
                else {
                    mg_printf(nc, "%s", "HTTP/1.1 200 OK\r\n");
                }
            }
            nc->flags &= ~MG_F_HTTP_CGI_PARSE_HEADERS;
        }
        if (!(nc->flags & MG_F_HTTP_CGI_PARSE_HEADERS)) {
            mg_forward(cgi_nc, nc);
        }
        break;
    case MG_EV_CLOSE:
        DBG(("%p CLOSE", cgi_nc));
        mg_http_free_proto_data_cgi(&mg_http_get_proto_data(nc)->cgi);
        nc->flags |= MG_F_SEND_AND_CLOSE;
        break;
    }
}

MG_INTERNAL void mg_handle_cgi(struct mg_connection *nc, const char *prog,
    const struct mg_str *path_info,
    const struct http_message *hm,
    const struct mg_serve_http_opts *opts) {
    struct mg_cgi_env_block blk;
    char dir[MG_MAX_PATH];
    const char *p;
    sock_t fds[2];

    DBG(("%p [%s]", nc, prog));
    mg_prepare_cgi_environment(nc, prog, path_info, hm, opts, &blk);
    /*
     * CGI must be executed in its own directory. 'dir' must point to the
     * directory containing executable program, 'p' must point to the
     * executable program name relative to 'dir'.
     */
    if ((p = strrchr(prog, DIRSEP)) == NULL) {
        snprintf(dir, sizeof(dir), "%s", ".");
    }
    else {
        snprintf(dir, sizeof(dir), "%.*s", (int)(p - prog), prog);
        prog = p + 1;
    }

    if (!mg_socketpair(fds, SOCK_STREAM)) {
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        return;
    }

#ifndef _WIN32
    struct sigaction sa;

    sigemptyset(&sa.sa_mask);
    sa.sa_handler = SIG_IGN;
    sa.sa_flags = 0;
    sigaction(SIGCHLD, &sa, NULL);
#endif

    if (mg_start_process(opts->cgi_interpreter, prog, blk.buf, blk.vars, dir,
        fds[1]) != 0) {
        struct mg_connection *cgi_nc =
            mg_add_sock(nc->mgr, fds[0], mg_cgi_ev_handler MG_UD_ARG(nc));
        struct mg_http_proto_data *cgi_pd = mg_http_get_proto_data(nc);
        cgi_pd->cgi.cgi_nc = cgi_nc;
#if !MG_ENABLE_CALLBACK_USERDATA
        cgi_pd->cgi.cgi_nc->user_data = nc;
#endif
        nc->flags |= MG_F_HTTP_CGI_PARSE_HEADERS;
        /* Push POST data to the CGI */
        if (hm->body.len > 0) {
            mg_send(cgi_pd->cgi.cgi_nc, hm->body.p, hm->body.len);
        }
        mbuf_remove(&nc->recv_mbuf, nc->recv_mbuf.len);
    }
    else {
        closesocket(fds[0]);
        mg_http_send_error(nc, 500, "CGI failure");
    }

#ifndef _WIN32
    closesocket(fds[1]); /* On Windows, CGI stdio thread closes that socket */
#endif
}

MG_INTERNAL void mg_http_free_proto_data_cgi(struct mg_http_proto_data_cgi *d) {
    if (d == NULL) return;
    if (d->cgi_nc != NULL) {
        d->cgi_nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        d->cgi_nc->user_data = NULL;
    }
    memset(d, 0, sizeof(*d));
}

#endif /* MG_ENABLE_HTTP && MG_ENABLE_HTTP_CGI */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_http_ssi.c"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_HTTP && MG_ENABLE_HTTP_SSI && MG_ENABLE_FILESYSTEM

static void mg_send_ssi_file(struct mg_connection *nc, struct http_message *hm,
    const char *path, FILE *fp, int include_level,
    const struct mg_serve_http_opts *opts);

static void mg_send_file_data(struct mg_connection *nc, FILE *fp) {
    char buf[BUFSIZ];
    size_t n;
    while ((n = mg_fread(buf, 1, sizeof(buf), fp)) > 0) {
        mg_send(nc, buf, n);
    }
}

static void mg_do_ssi_include(struct mg_connection *nc, struct http_message *hm,
    const char *ssi, char *tag, int include_level,
    const struct mg_serve_http_opts *opts) {
    char file_name[MG_MAX_PATH], path[MG_MAX_PATH], *p;
    FILE *fp;

    /*
     * sscanf() is safe here, since send_ssi_file() also uses buffer
     * of size MG_BUF_LEN to get the tag. So strlen(tag) is always < MG_BUF_LEN.
     */
    if (sscanf(tag, " virtual=\"%[^\"]\"", file_name) == 1) {
        /* File name is relative to the webserver root */
        snprintf(path, sizeof(path), "%s/%s", opts->document_root, file_name);
    }
    else if (sscanf(tag, " abspath=\"%[^\"]\"", file_name) == 1) {
        /*
         * File name is relative to the webserver working directory
         * or it is absolute system path
         */
        snprintf(path, sizeof(path), "%s", file_name);
    }
    else if (sscanf(tag, " file=\"%[^\"]\"", file_name) == 1 ||
        sscanf(tag, " \"%[^\"]\"", file_name) == 1) {
        /* File name is relative to the currect document */
        snprintf(path, sizeof(path), "%s", ssi);
        if ((p = strrchr(path, DIRSEP)) != NULL) {
            p[1] = '\0';
        }
        snprintf(path + strlen(path), sizeof(path) - strlen(path), "%s", file_name);
    }
    else {
        mg_printf(nc, "Bad SSI #include: [%s]", tag);
        return;
    }

    if ((fp = mg_fopen(path, "rb")) == NULL) {
        mg_printf(nc, "SSI include error: mg_fopen(%s): %s", path,
            strerror(mg_get_errno()));
    }
    else {
        mg_set_close_on_exec((sock_t)fileno(fp));
        if (mg_match_prefix(opts->ssi_pattern, strlen(opts->ssi_pattern), path) >
            0) {
            mg_send_ssi_file(nc, hm, path, fp, include_level + 1, opts);
        }
        else {
            mg_send_file_data(nc, fp);
        }
        fclose(fp);
    }
}

#if MG_ENABLE_HTTP_SSI_EXEC
static void do_ssi_exec(struct mg_connection *nc, char *tag) {
    char cmd[BUFSIZ];
    FILE *fp;

    if (sscanf(tag, " \"%[^\"]\"", cmd) != 1) {
        mg_printf(nc, "Bad SSI #exec: [%s]", tag);
    }
    else if ((fp = popen(cmd, "r")) == NULL) {
        mg_printf(nc, "Cannot SSI #exec: [%s]: %s", cmd, strerror(mg_get_errno()));
    }
    else {
        mg_send_file_data(nc, fp);
        pclose(fp);
    }
}
#endif /* MG_ENABLE_HTTP_SSI_EXEC */

/*
 * SSI directive has the following format:
 * <!--#directive parameter=value parameter=value -->
 */
static void mg_send_ssi_file(struct mg_connection *nc, struct http_message *hm,
    const char *path, FILE *fp, int include_level,
    const struct mg_serve_http_opts *opts) {
    static const struct mg_str btag = MG_MK_STR("<!--#");
    static const struct mg_str d_include = MG_MK_STR("include");
    static const struct mg_str d_call = MG_MK_STR("call");
#if MG_ENABLE_HTTP_SSI_EXEC
    static const struct mg_str d_exec = MG_MK_STR("exec");
#endif
    char buf[BUFSIZ], *p = buf + btag.len; /* p points to SSI directive */
    int ch, len, in_ssi_tag;

    if (include_level > 10) {
        mg_printf(nc, "SSI #include level is too deep (%s)", path);
        return;
    }

    in_ssi_tag = len = 0;
    while ((ch = fgetc(fp)) != EOF) {
        if (in_ssi_tag && ch == '>' && buf[len - 1] == '-' && buf[len - 2] == '-') {
            size_t i = len - 2;
            in_ssi_tag = 0;

            /* Trim closing --> */
            buf[i--] = '\0';
            while (i > 0 && buf[i] == ' ') {
                buf[i--] = '\0';
            }

            /* Handle known SSI directives */
            if (strncmp(p, d_include.p, d_include.len) == 0) {
                mg_do_ssi_include(nc, hm, path, p + d_include.len + 1, include_level,
                    opts);
            }
            else if (strncmp(p, d_call.p, d_call.len) == 0) {
                struct mg_ssi_call_ctx cctx;
                memset(&cctx, 0, sizeof(cctx));
                cctx.req = hm;
                cctx.file = mg_mk_str(path);
                cctx.arg = mg_mk_str(p + d_call.len + 1);
                mg_call(nc, NULL, nc->user_data, MG_EV_SSI_CALL,
                    (void *)cctx.arg.p); /* NUL added above */
                mg_call(nc, NULL, nc->user_data, MG_EV_SSI_CALL_CTX, &cctx);
#if MG_ENABLE_HTTP_SSI_EXEC
            }
            else if (strncmp(p, d_exec.p, d_exec.len) == 0) {
                do_ssi_exec(nc, p + d_exec.len + 1);
#endif
            }
            else {
                /* Silently ignore unknown SSI directive. */
            }
            len = 0;
        }
        else if (ch == '<') {
            in_ssi_tag = 1;
            if (len > 0) {
                mg_send(nc, buf, (size_t)len);
            }
            len = 0;
            buf[len++] = ch & 0xff;
        }
        else if (in_ssi_tag) {
            if (len == (int)btag.len && strncmp(buf, btag.p, btag.len) != 0) {
                /* Not an SSI tag */
                in_ssi_tag = 0;
            }
            else if (len == (int) sizeof(buf) - 2) {
                mg_printf(nc, "%s: SSI tag is too large", path);
                len = 0;
            }
            buf[len++] = ch & 0xff;
        }
        else {
            buf[len++] = ch & 0xff;
            if (len == (int) sizeof(buf)) {
                mg_send(nc, buf, (size_t)len);
                len = 0;
            }
        }
    }

    /* Send the rest of buffered data */
    if (len > 0) {
        mg_send(nc, buf, (size_t)len);
    }
}

MG_INTERNAL void mg_handle_ssi_request(struct mg_connection *nc,
    struct http_message *hm,
    const char *path,
    const struct mg_serve_http_opts *opts) {
    FILE *fp;
    struct mg_str mime_type;
    DBG(("%p %s", nc, path));

    if ((fp = mg_fopen(path, "rb")) == NULL) {
        mg_http_send_error(nc, 404, NULL);
    }
    else {
        mg_set_close_on_exec((sock_t)fileno(fp));

        mime_type = mg_get_mime_type(path, "text/plain", opts);
        mg_send_response_line(nc, 200, opts->extra_headers);
        mg_printf(nc,
            "Content-Type: %.*s\r\n"
            "Connection: close\r\n\r\n",
            (int)mime_type.len, mime_type.p);
        mg_send_ssi_file(nc, hm, path, fp, 0, opts);
        fclose(fp);
        nc->flags |= MG_F_SEND_AND_CLOSE;
    }
}

#endif /* MG_ENABLE_HTTP_SSI && MG_ENABLE_HTTP && MG_ENABLE_FILESYSTEM */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_http_webdav.c"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_HTTP && MG_ENABLE_HTTP_WEBDAV

MG_INTERNAL int mg_is_dav_request(const struct mg_str *s) {
    static const char *methods[] = {
      "PUT",
      "DELETE",
      "MKCOL",
      "PROPFIND",
      "MOVE"
  #if MG_ENABLE_FAKE_DAVLOCK
      ,
      "LOCK",
      "UNLOCK"
  #endif
    };
    size_t i;

    for (i = 0; i < ARRAY_SIZE(methods); i++) {
        if (mg_vcmp(s, methods[i]) == 0) {
            return 1;
        }
    }

    return 0;
}

static int mg_mkdir(const char *path, uint32_t mode) {
#ifndef _WIN32
    return mkdir(path, mode);
#else
    (void)mode;
    return _mkdir(path);
#endif
}

static void mg_print_props(struct mg_connection *nc, const char *name,
    cs_stat_t *stp) {
    char mtime[64];
    time_t t = stp->st_mtime; /* store in local variable for NDK compile */
    struct mg_str name_esc = mg_url_encode(mg_mk_str(name));
    mg_gmt_time_string(mtime, sizeof(mtime), &t);
    mg_printf(nc,
        "<d:response>"
        "<d:href>%s</d:href>"
        "<d:propstat>"
        "<d:prop>"
        "<d:resourcetype>%s</d:resourcetype>"
        "<d:getcontentlength>%" INT64_FMT
        "</d:getcontentlength>"
        "<d:getlastmodified>%s</d:getlastmodified>"
        "</d:prop>"
        "<d:status>HTTP/1.1 200 OK</d:status>"
        "</d:propstat>"
        "</d:response>\n",
        name_esc.p, S_ISDIR(stp->st_mode) ? "<d:collection/>" : "",
        (int64_t)stp->st_size, mtime);
    free((void *)name_esc.p);
}

MG_INTERNAL void mg_handle_propfind(struct mg_connection *nc, const char *path,
    cs_stat_t *stp, struct http_message *hm,
    struct mg_serve_http_opts *opts) {
    static const char header[] =
        "HTTP/1.1 207 Multi-Status\r\n"
        "Connection: close\r\n"
        "Content-Type: text/xml; charset=utf-8\r\n\r\n"
        "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
        "<d:multistatus xmlns:d='DAV:'>\n";
    static const char footer[] = "</d:multistatus>\n";
    const struct mg_str *depth = mg_get_http_header(hm, "Depth");

    /* Print properties for the requested resource itself */
    if (S_ISDIR(stp->st_mode) &&
        strcmp(opts->enable_directory_listing, "yes") != 0) {
        mg_printf(nc, "%s", "HTTP/1.1 403 Directory Listing Denied\r\n\r\n");
    }
    else {
        char uri[MG_MAX_PATH];
        mg_send(nc, header, sizeof(header) - 1);
        snprintf(uri, sizeof(uri), "%.*s", (int)hm->uri.len, hm->uri.p);
        mg_print_props(nc, uri, stp);
        if (S_ISDIR(stp->st_mode) && (depth == NULL || mg_vcmp(depth, "0") != 0)) {
            mg_scan_directory(nc, path, opts, mg_print_props);
        }
        mg_send(nc, footer, sizeof(footer) - 1);
        nc->flags |= MG_F_SEND_AND_CLOSE;
    }
}

#if MG_ENABLE_FAKE_DAVLOCK
/*
 * Windows explorer (probably there are another WebDav clients like it)
 * requires LOCK support in webdav. W/out this, it still works, but fails
 * to save file: shows error message and offers "Save As".
 * "Save as" works, but this message is very annoying.
 * This is fake lock, which doesn't lock something, just returns LOCK token,
 * UNLOCK always answers "OK".
 * With this fake LOCK Windows Explorer looks happy and saves file.
 * NOTE: that is not DAV LOCK imlementation, it is just a way to shut up
 * Windows native DAV client. This is why FAKE LOCK is not enabed by default
 */
MG_INTERNAL void mg_handle_lock(struct mg_connection *nc, const char *path) {
    static const char *reply =
        "HTTP/1.1 207 Multi-Status\r\n"
        "Connection: close\r\n"
        "Content-Type: text/xml; charset=utf-8\r\n\r\n"
        "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
        "<d:multistatus xmlns:d='DAV:'>\n"
        "<D:lockdiscovery>\n"
        "<D:activelock>\n"
        "<D:locktoken>\n"
        "<D:href>\n"
        "opaquelocktoken:%s%u"
        "</D:href>"
        "</D:locktoken>"
        "</D:activelock>\n"
        "</D:lockdiscovery>"
        "</d:multistatus>\n";
    mg_printf(nc, reply, path, (unsigned int)mg_time());
    nc->flags |= MG_F_SEND_AND_CLOSE;
}
#endif

MG_INTERNAL void mg_handle_mkcol(struct mg_connection *nc, const char *path,
    struct http_message *hm) {
    int status_code = 500;
    if (hm->body.len != (size_t)~0 && hm->body.len > 0) {
        status_code = 415;
    }
    else if (!mg_mkdir(path, 0755)) {
        status_code = 201;
    }
    else if (errno == EEXIST) {
        status_code = 405;
    }
    else if (errno == EACCES) {
        status_code = 403;
    }
    else if (errno == ENOENT) {
        status_code = 409;
    }
    else {
        status_code = 500;
    }
    mg_http_send_error(nc, status_code, NULL);
}

static int mg_remove_directory(const struct mg_serve_http_opts *opts,
    const char *dir) {
    char path[MG_MAX_PATH];
    struct dirent *dp;
    cs_stat_t st;
    DIR *dirp;

    if ((dirp = opendir(dir)) == NULL) return 0;

    while ((dp = readdir(dirp)) != NULL) {
        if (mg_is_file_hidden((const char *)dp->d_name, opts, 1)) {
            continue;
        }
        snprintf(path, sizeof(path), "%s%c%s", dir, '/', dp->d_name);
        mg_stat(path, &st);
        if (S_ISDIR(st.st_mode)) {
            mg_remove_directory(opts, path);
        }
        else {
            remove(path);
        }
    }
    closedir(dirp);
    rmdir(dir);

    return 1;
}

MG_INTERNAL void mg_handle_move(struct mg_connection *c,
    const struct mg_serve_http_opts *opts,
    const char *path, struct http_message *hm) {
    const struct mg_str *dest = mg_get_http_header(hm, "Destination");
    if (dest == NULL) {
        mg_http_send_error(c, 411, NULL);
    }
    else {
        const char *p = (char *)memchr(dest->p, '/', dest->len);
        if (p != NULL && p[1] == '/' &&
            (p = (char *)memchr(p + 2, '/', dest->p + dest->len - p)) != NULL) {
            char buf[MG_MAX_PATH];
            snprintf(buf, sizeof(buf), "%s%.*s", opts->dav_document_root,
                (int)(dest->p + dest->len - p), p);
            if (rename(path, buf) == 0) {
                mg_http_send_error(c, 200, NULL);
            }
            else {
                mg_http_send_error(c, 418, NULL);
            }
        }
        else {
            mg_http_send_error(c, 500, NULL);
        }
    }
}

MG_INTERNAL void mg_handle_delete(struct mg_connection *nc,
    const struct mg_serve_http_opts *opts,
    const char *path) {
    cs_stat_t st;
    if (mg_stat(path, &st) != 0) {
        mg_http_send_error(nc, 404, NULL);
    }
    else if (S_ISDIR(st.st_mode)) {
        mg_remove_directory(opts, path);
        mg_http_send_error(nc, 204, NULL);
    }
    else if (remove(path) == 0) {
        mg_http_send_error(nc, 204, NULL);
    }
    else {
        mg_http_send_error(nc, 423, NULL);
    }
}

/* Return -1 on error, 1 on success. */
static int mg_create_itermediate_directories(const char *path) {
    const char *s;

    /* Create intermediate directories if they do not exist */
    for (s = path + 1; *s != '\0'; s++) {
        if (*s == '/') {
            char buf[MG_MAX_PATH];
            cs_stat_t st;
            snprintf(buf, sizeof(buf), "%.*s", (int)(s - path), path);
            buf[sizeof(buf) - 1] = '\0';
            if (mg_stat(buf, &st) != 0 && mg_mkdir(buf, 0755) != 0) {
                return -1;
            }
        }
    }

    return 1;
}

MG_INTERNAL void mg_handle_put(struct mg_connection *nc, const char *path,
    struct http_message *hm) {
    struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
    cs_stat_t st;
    const struct mg_str *cl_hdr = mg_get_http_header(hm, "Content-Length");
    int rc, status_code = mg_stat(path, &st) == 0 ? 200 : 201;

    mg_http_free_proto_data_file(&pd->file);
    if ((rc = mg_create_itermediate_directories(path)) == 0) {
        mg_printf(nc, "HTTP/1.1 %d OK\r\nContent-Length: 0\r\n\r\n", status_code);
    }
    else if (rc == -1) {
        mg_http_send_error(nc, 500, NULL);
    }
    else if (cl_hdr == NULL) {
        mg_http_send_error(nc, 411, NULL);
    }
    else if ((pd->file.fp = mg_fopen(path, "w+b")) == NULL) {
        mg_http_send_error(nc, 500, NULL);
    }
    else {
        const struct mg_str *range_hdr = mg_get_http_header(hm, "Content-Range");
        int64_t r1 = 0, r2 = 0;
        pd->file.type = DATA_PUT;
        mg_set_close_on_exec((sock_t)fileno(pd->file.fp));
        pd->file.cl = to64(cl_hdr->p);
        if (range_hdr != NULL &&
            mg_http_parse_range_header(range_hdr, &r1, &r2) > 0) {
            status_code = 206;
            fseeko(pd->file.fp, r1, SEEK_SET);
            pd->file.cl = r2 > r1 ? r2 - r1 + 1 : pd->file.cl - r1;
        }
        mg_printf(nc, "HTTP/1.1 %d OK\r\nContent-Length: 0\r\n\r\n", status_code);
        /* Remove HTTP request from the mbuf, leave only payload */
        mbuf_remove(&nc->recv_mbuf, hm->message.len - hm->body.len);
        mg_http_transfer_file_data(nc);
    }
}

#endif /* MG_ENABLE_HTTP && MG_ENABLE_HTTP_WEBDAV */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_http_websocket.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_HTTP && MG_ENABLE_HTTP_WEBSOCKET

 /* Amalgamated: #include "common/cs_sha1.h" */

#ifndef MG_WEBSOCKET_PING_INTERVAL_SECONDS
#define MG_WEBSOCKET_PING_INTERVAL_SECONDS 5
#endif

#define FLAGS_MASK_FIN (1 << 7)
#define FLAGS_MASK_OP 0x0f

static int mg_is_ws_fragment(unsigned char flags) {
    return (flags & FLAGS_MASK_FIN) == 0 ||
        (flags & FLAGS_MASK_OP) == WEBSOCKET_OP_CONTINUE;
}

static int mg_is_ws_first_fragment(unsigned char flags) {
    return (flags & FLAGS_MASK_FIN) == 0 &&
        (flags & FLAGS_MASK_OP) != WEBSOCKET_OP_CONTINUE;
}

static int mg_is_ws_control_frame(unsigned char flags) {
    unsigned char op = (flags & FLAGS_MASK_OP);
    return op == WEBSOCKET_OP_CLOSE || op == WEBSOCKET_OP_PING ||
        op == WEBSOCKET_OP_PONG;
}

static void mg_handle_incoming_websocket_frame(struct mg_connection *nc,
    struct websocket_message *wsm) {
    if (wsm->flags & 0x8) {
        mg_call(nc, nc->handler, nc->user_data, MG_EV_WEBSOCKET_CONTROL_FRAME, wsm);
    }
    else {
        mg_call(nc, nc->handler, nc->user_data, MG_EV_WEBSOCKET_FRAME, wsm);
    }
}

static struct mg_ws_proto_data *mg_ws_get_proto_data(struct mg_connection *nc) {
    struct mg_http_proto_data *htd = mg_http_get_proto_data(nc);
    return (htd != NULL ? &htd->ws_data : NULL);
}

/*
 * Sends a Close websocket frame with the given data, and closes the underlying
 * connection. If `len` is ~0, strlen(data) is used.
 */
static void mg_ws_close(struct mg_connection *nc, const void *data,
    size_t len) {
    if ((int)len == ~0) {
        len = strlen((const char *)data);
    }
    mg_send_websocket_frame(nc, WEBSOCKET_OP_CLOSE, data, len);
    nc->flags |= MG_F_SEND_AND_CLOSE;
}

static int mg_deliver_websocket_data(struct mg_connection *nc) {
    /* Using unsigned char *, cause of integer arithmetic below */
    uint64_t i, data_len = 0, frame_len = 0, new_data_len = nc->recv_mbuf.len,
        len, mask_len = 0, header_len = 0;
    struct mg_ws_proto_data *wsd = mg_ws_get_proto_data(nc);
    unsigned char *new_data = (unsigned char *)nc->recv_mbuf.buf,
        *e = (unsigned char *)nc->recv_mbuf.buf + nc->recv_mbuf.len;
    uint8_t flags;
    int ok, reass;

    if (wsd->reass_len > 0) {
        /*
         * We already have some previously received data which we need to
         * reassemble and deliver to the client code when we get the final
         * fragment.
         *
         * NOTE: it doesn't mean that the current message must be a continuation:
         * it might be a control frame (Close, Ping or Pong), which should be
         * handled without breaking the fragmented message.
         */

        size_t existing_len = wsd->reass_len;
        assert(new_data_len >= existing_len);

        new_data += existing_len;
        new_data_len -= existing_len;
    }

    flags = new_data[0];

    reass = new_data_len > 0 && mg_is_ws_fragment(flags) &&
        !(nc->flags & MG_F_WEBSOCKET_NO_DEFRAG);

    if (reass && mg_is_ws_control_frame(flags)) {
        /*
         * Control frames can't be fragmented, so if we encounter fragmented
         * control frame, close connection immediately.
         */
        mg_ws_close(nc, "fragmented control frames are illegal", ~0);
        return 0;
    }
    else if (new_data_len > 0 && !reass && !mg_is_ws_control_frame(flags) &&
        wsd->reass_len > 0) {
        /*
         * When in the middle of a fragmented message, only the continuations
         * and control frames are allowed.
         */
        mg_ws_close(nc, "non-continuation in the middle of a fragmented message",
            ~0);
        return 0;
    }

    if (new_data_len >= 2) {
        len = new_data[1] & 0x7f;
        mask_len = new_data[1] & FLAGS_MASK_FIN ? 4 : 0;
        if (len < 126 && new_data_len >= mask_len) {
            data_len = len;
            header_len = 2 + mask_len;
        }
        else if (len == 126 && new_data_len >= 4 + mask_len) {
            header_len = 4 + mask_len;
            data_len = ntohs(*(uint16_t *)&new_data[2]);
        }
        else if (new_data_len >= 10 + mask_len) {
            header_len = 10 + mask_len;
            data_len = (((uint64_t)ntohl(*(uint32_t *)&new_data[2])) << 32) +
                ntohl(*(uint32_t *)&new_data[6]);
        }
    }

    frame_len = header_len + data_len;
    ok = (frame_len > 0 && frame_len <= new_data_len);

    /* Check for overflow */
    if (frame_len < header_len || frame_len < data_len) {
        ok = 0;
        mg_ws_close(nc, "overflowed message", ~0);
    }

    if (ok) {
        size_t cleanup_len = 0;
        struct websocket_message wsm;

        wsm.size = (size_t)data_len;
        wsm.data = new_data + header_len;
        wsm.flags = flags;

        /* Apply mask if necessary */
        if (mask_len > 0) {
            for (i = 0; i < data_len; i++) {
                new_data[i + header_len] ^= (new_data + header_len - mask_len)[i % 4];
            }
        }

        if (reass) {
            /* This is a message fragment */

            if (mg_is_ws_first_fragment(flags)) {
                /*
                 * On the first fragmented frame, skip the first byte (op) and also
                 * reset size to 1 (op), it'll be incremented with the data len below.
                 */
                new_data += 1;
                wsd->reass_len = 1 /* op */;
            }

            /* Append this frame to the reassembled buffer */
            memmove(new_data, wsm.data, e - wsm.data);
            wsd->reass_len += wsm.size;
            nc->recv_mbuf.len -= wsm.data - new_data;

            if (flags & FLAGS_MASK_FIN) {
                /* On last fragmented frame - call user handler and remove data */
                wsm.flags = FLAGS_MASK_FIN | nc->recv_mbuf.buf[0];
                wsm.data = (unsigned char *)nc->recv_mbuf.buf + 1 /* op */;
                wsm.size = wsd->reass_len - 1 /* op */;
                cleanup_len = wsd->reass_len;
                wsd->reass_len = 0;

                /* Pass reassembled message to the client code. */
                mg_handle_incoming_websocket_frame(nc, &wsm);
                mbuf_remove(&nc->recv_mbuf, cleanup_len); /* Cleanup frame */
            }
        }
        else {
            /*
             * This is a complete message, not a fragment. It might happen in between
             * of a fragmented message (in this case, WebSocket protocol requires
             * current message to be a control frame).
             */
            cleanup_len = (size_t)frame_len;

            /* First of all, check if we need to react on a control frame. */
            switch (flags & FLAGS_MASK_OP) {
            case WEBSOCKET_OP_PING:
                mg_send_websocket_frame(nc, WEBSOCKET_OP_PONG, wsm.data, wsm.size);
                break;

            case WEBSOCKET_OP_CLOSE:
                mg_ws_close(nc, wsm.data, wsm.size);
                break;
            }

            /* Pass received message to the client code. */
            mg_handle_incoming_websocket_frame(nc, &wsm);

            /* Cleanup frame */
            memmove(nc->recv_mbuf.buf + wsd->reass_len,
                nc->recv_mbuf.buf + wsd->reass_len + cleanup_len,
                nc->recv_mbuf.len - wsd->reass_len - cleanup_len);
            nc->recv_mbuf.len -= cleanup_len;
        }
    }

    return ok;
}

struct ws_mask_ctx {
    size_t pos; /* zero means unmasked */
    uint32_t mask;
};

static uint32_t mg_ws_random_mask(void) {
    uint32_t mask;
    /*
     * The spec requires WS client to generate hard to
     * guess mask keys. From RFC6455, Section 5.3:
     *
     * The unpredictability of the masking key is essential to prevent
     * authors of malicious applications from selecting the bytes that appear on
     * the wire.
     *
     * Hence this feature is essential when the actual end user of this API
     * is untrusted code that wouldn't have access to a lower level net API
     * anyway (e.g. web browsers). Hence this feature is low prio for most
     * mongoose use cases and thus can be disabled, e.g. when porting to a platform
     * that lacks rand().
     */
#if MG_DISABLE_WS_RANDOM_MASK
    mask = 0xefbeadde; /* generated with a random number generator, I swear */
#else
    if (sizeof(long) >= 4) {
        mask = (uint32_t)rand();
    }
    else if (sizeof(long) == 2) {
        mask = (uint32_t)rand() << 16 | (uint32_t)rand();
    }
#endif
    return mask;
}

static void mg_send_ws_header(struct mg_connection *nc, int op, size_t len,
    struct ws_mask_ctx *ctx) {
    int header_len;
    unsigned char header[10];

    header[0] =
        (op & WEBSOCKET_DONT_FIN ? 0x0 : FLAGS_MASK_FIN) | (op & FLAGS_MASK_OP);
    if (len < 126) {
        header[1] = (unsigned char)len;
        header_len = 2;
    }
    else if (len < 65535) {
        uint16_t tmp = htons((uint16_t)len);
        header[1] = 126;
        memcpy(&header[2], &tmp, sizeof(tmp));
        header_len = 4;
    }
    else {
        uint32_t tmp;
        header[1] = 127;
        tmp = htonl((uint32_t)((uint64_t)len >> 32));
        memcpy(&header[2], &tmp, sizeof(tmp));
        tmp = htonl((uint32_t)(len & 0xffffffff));
        memcpy(&header[6], &tmp, sizeof(tmp));
        header_len = 10;
    }

    /* client connections enable masking */
    if (nc->listener == NULL) {
        header[1] |= 1 << 7; /* set masking flag */
        mg_send(nc, header, header_len);
        ctx->mask = mg_ws_random_mask();
        mg_send(nc, &ctx->mask, sizeof(ctx->mask));
        ctx->pos = nc->send_mbuf.len;
    }
    else {
        mg_send(nc, header, header_len);
        ctx->pos = 0;
    }
}

static void mg_ws_mask_frame(struct mbuf *mbuf, struct ws_mask_ctx *ctx) {
    size_t i;
    if (ctx->pos == 0) return;
    for (i = 0; i < (mbuf->len - ctx->pos); i++) {
        mbuf->buf[ctx->pos + i] ^= ((char *)&ctx->mask)[i % 4];
    }
}

void mg_send_websocket_frame(struct mg_connection *nc, int op, const void *data,
    size_t len) {
    struct ws_mask_ctx ctx;
    DBG(("%p %d %d", nc, op, (int)len));
    mg_send_ws_header(nc, op, len, &ctx);
    mg_send(nc, data, len);

    mg_ws_mask_frame(&nc->send_mbuf, &ctx);

    if (op == WEBSOCKET_OP_CLOSE) {
        nc->flags |= MG_F_SEND_AND_CLOSE;
    }
}

void mg_send_websocket_framev(struct mg_connection *nc, int op,
    const struct mg_str *strv, int strvcnt) {
    struct ws_mask_ctx ctx;
    int i;
    int len = 0;
    for (i = 0; i < strvcnt; i++) {
        len += strv[i].len;
    }

    mg_send_ws_header(nc, op, len, &ctx);

    for (i = 0; i < strvcnt; i++) {
        mg_send(nc, strv[i].p, strv[i].len);
    }

    mg_ws_mask_frame(&nc->send_mbuf, &ctx);

    if (op == WEBSOCKET_OP_CLOSE) {
        nc->flags |= MG_F_SEND_AND_CLOSE;
    }
}

void mg_printf_websocket_frame(struct mg_connection *nc, int op,
    const char *fmt, ...) {
    char mem[MG_VPRINTF_BUFFER_SIZE], *buf = mem;
    va_list ap;
    int len;

    va_start(ap, fmt);
    if ((len = mg_avprintf(&buf, sizeof(mem), fmt, ap)) > 0) {
        mg_send_websocket_frame(nc, op, buf, len);
    }
    va_end(ap);

    if (buf != mem && buf != NULL) {
        MG_FREE(buf);
    }
}

MG_INTERNAL void mg_ws_handler(struct mg_connection *nc, int ev,
    void *ev_data MG_UD_ARG(void *user_data)) {
    mg_call(nc, nc->handler, nc->user_data, ev, ev_data);

    switch (ev) {
    case MG_EV_RECV:
        do {
        } while (mg_deliver_websocket_data(nc));
        break;
    case MG_EV_POLL:
        /* Ping idle websocket connections */
    {
        time_t now = *(time_t *)ev_data;
        if (nc->flags & MG_F_IS_WEBSOCKET &&
            now > nc->last_io_time + MG_WEBSOCKET_PING_INTERVAL_SECONDS) {
            mg_send_websocket_frame(nc, WEBSOCKET_OP_PING, "", 0);
        }
    }
    break;
    default:
        break;
    }
#if MG_ENABLE_CALLBACK_USERDATA
    (void) user_data;
#endif
}

#ifndef MG_EXT_SHA1
void mg_hash_sha1_v(size_t num_msgs, const uint8_t *msgs[],
    const size_t *msg_lens, uint8_t *digest) {
    size_t i;
    cs_sha1_ctx sha_ctx;
    cs_sha1_init(&sha_ctx);
    for (i = 0; i < num_msgs; i++) {
        cs_sha1_update(&sha_ctx, msgs[i], msg_lens[i]);
    }
    cs_sha1_final(digest, &sha_ctx);
}
#else
extern void mg_hash_sha1_v(size_t num_msgs, const uint8_t *msgs[],
    const size_t *msg_lens, uint8_t *digest);
#endif

MG_INTERNAL void mg_ws_handshake(struct mg_connection *nc,
    const struct mg_str *key,
    struct http_message *hm) {
    static const char *magic = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
    const uint8_t *msgs[2] = { (const uint8_t *)key->p, (const uint8_t *)magic };
    const size_t msg_lens[2] = { key->len, 36 };
    unsigned char sha[20];
    char b64_sha[30];
    struct mg_str *s;

    mg_hash_sha1_v(2, msgs, msg_lens, sha);
    mg_base64_encode(sha, sizeof(sha), b64_sha);
    mg_printf(nc, "%s",
        "HTTP/1.1 101 Switching Protocols\r\n"
        "Upgrade: websocket\r\n"
        "Connection: Upgrade\r\n");

    s = mg_get_http_header(hm, "Sec-WebSocket-Protocol");
    if (s != NULL) {
        mg_printf(nc, "Sec-WebSocket-Protocol: %.*s\r\n", (int)s->len, s->p);
    }
    mg_printf(nc, "Sec-WebSocket-Accept: %s%s", b64_sha, "\r\n\r\n");

    DBG(("%p %.*s %s", nc, (int)key->len, key->p, b64_sha));
}

void mg_send_websocket_handshake2(struct mg_connection *nc, const char *path,
    const char *host, const char *protocol,
    const char *extra_headers) {
    mg_send_websocket_handshake3(nc, path, host, protocol, extra_headers, NULL,
        NULL);
}

void mg_send_websocket_handshake3(struct mg_connection *nc, const char *path,
    const char *host, const char *protocol,
    const char *extra_headers, const char *user,
    const char *pass) {
    mg_send_websocket_handshake3v(nc, mg_mk_str(path), mg_mk_str(host),
        mg_mk_str(protocol), mg_mk_str(extra_headers),
        mg_mk_str(user), mg_mk_str(pass));
}

void mg_send_websocket_handshake3v(struct mg_connection *nc,
    const struct mg_str path,
    const struct mg_str host,
    const struct mg_str protocol,
    const struct mg_str extra_headers,
    const struct mg_str user,
    const struct mg_str pass) {
    struct mbuf auth;
    char key[25];
    uint32_t nonce[4];
    nonce[0] = mg_ws_random_mask();
    nonce[1] = mg_ws_random_mask();
    nonce[2] = mg_ws_random_mask();
    nonce[3] = mg_ws_random_mask();
    mg_base64_encode((unsigned char *)&nonce, sizeof(nonce), key);

    mbuf_init(&auth, 0);
    if (user.len > 0) {
        mg_basic_auth_header(user, pass, &auth);
    }

    /*
     * NOTE: the  (auth.buf == NULL ? "" : auth.buf) is because cc3200 libc is
     * broken: it doesn't like zero length to be passed to %.*s
     * i.e. sprintf("f%.*so", (int)0, NULL), yields `f\0o`.
     * because it handles NULL specially (and incorrectly).
     */
    mg_printf(nc,
        "GET %.*s HTTP/1.1\r\n"
        "Upgrade: websocket\r\n"
        "Connection: Upgrade\r\n"
        "%.*s"
        "Sec-WebSocket-Version: 13\r\n"
        "Sec-WebSocket-Key: %s\r\n",
        (int)path.len, path.p, (int)auth.len,
        (auth.buf == NULL ? "" : auth.buf), key);

    /* TODO(mkm): take default hostname from http proto data if host == NULL */
    if (host.len > 0) {
        int host_len = (int)(path.p - host.p); /* Account for possible :PORT */
        mg_printf(nc, "Host: %.*s\r\n", host_len, host.p);
    }
    if (protocol.len > 0) {
        mg_printf(nc, "Sec-WebSocket-Protocol: %.*s\r\n", (int)protocol.len,
            protocol.p);
    }
    if (extra_headers.len > 0) {
        mg_printf(nc, "%.*s", (int)extra_headers.len, extra_headers.p);
    }
    mg_printf(nc, "\r\n");

    nc->flags |= MG_F_IS_WEBSOCKET;

    mbuf_free(&auth);
}

void mg_send_websocket_handshake(struct mg_connection *nc, const char *path,
    const char *extra_headers) {
    struct mg_str null_str = MG_NULL_STR;
    mg_send_websocket_handshake3v(
        nc, mg_mk_str(path), null_str /* host */, null_str /* protocol */,
        mg_mk_str(extra_headers), null_str /* user */, null_str /* pass */);
}

struct mg_connection *mg_connect_ws_opt(
    struct mg_mgr *mgr, MG_CB(mg_event_handler_t ev_handler, void *user_data),
    struct mg_connect_opts opts, const char *url, const char *protocol,
    const char *extra_headers) {
    struct mg_str null_str = MG_NULL_STR;
    struct mg_str host = MG_NULL_STR, path = MG_NULL_STR, user_info = MG_NULL_STR;
    struct mg_connection *nc =
        mg_connect_http_base(mgr, MG_CB(ev_handler, user_data), opts, "http",
            "ws", "https", "wss", url, &path, &user_info, &host);
    if (nc != NULL) {
        mg_send_websocket_handshake3v(nc, path, host, mg_mk_str(protocol),
            mg_mk_str(extra_headers), user_info,
            null_str);
    }
    return nc;
}

struct mg_connection *mg_connect_ws(
    struct mg_mgr *mgr, MG_CB(mg_event_handler_t ev_handler, void *user_data),
    const char *url, const char *protocol, const char *extra_headers) {
    struct mg_connect_opts opts;
    memset(&opts, 0, sizeof(opts));
    return mg_connect_ws_opt(mgr, MG_CB(ev_handler, user_data), opts, url,
        protocol, extra_headers);
}
#endif /* MG_ENABLE_HTTP && MG_ENABLE_HTTP_WEBSOCKET */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_util.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

 /* Amalgamated: #include "common/cs_base64.h" */
 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "mg_util.h" */

 /* For platforms with limited libc */
#ifndef MAX
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#endif

const char *mg_skip(const char *s, const char *end, const char *delims,
    struct mg_str *v) {
    v->p = s;
    while (s < end && strchr(delims, *(unsigned char *)s) == NULL) s++;
    v->len = s - v->p;
    while (s < end && strchr(delims, *(unsigned char *)s) != NULL) s++;
    return s;
}

#if MG_ENABLE_FILESYSTEM && !defined(MG_USER_FILE_FUNCTIONS)
int mg_stat(const char *path, cs_stat_t *st) {
#ifdef _WIN32
    wchar_t wpath[MG_MAX_PATH];
    to_wchar(path, wpath, ARRAY_SIZE(wpath));
    DBG(("[%ls] -> %d", wpath, _wstati64(wpath, st)));
    return _wstati64(wpath, st);
#else
    return stat(path, st);
#endif
}

FILE *mg_fopen(const char *path, const char *mode) {
#ifdef _WIN32
    wchar_t wpath[MG_MAX_PATH], wmode[10];
    to_wchar(path, wpath, ARRAY_SIZE(wpath));
    to_wchar(mode, wmode, ARRAY_SIZE(wmode));
    return _wfopen(wpath, wmode);
#else
    return fopen(path, mode);
#endif
}

int mg_open(const char *path, int flag, int mode) { /* LCOV_EXCL_LINE */
#if defined(_WIN32) && !defined(WINCE)
    wchar_t wpath[MG_MAX_PATH];
    to_wchar(path, wpath, ARRAY_SIZE(wpath));
    return _wopen(wpath, flag, mode);
#else
    return open(path, flag, mode); /* LCOV_EXCL_LINE */
#endif
}

size_t mg_fread(void *ptr, size_t size, size_t count, FILE *f) {
    return fread(ptr, size, count, f);
}

size_t mg_fwrite(const void *ptr, size_t size, size_t count, FILE *f) {
    return fwrite(ptr, size, count, f);
}
#endif

void mg_base64_encode(const unsigned char *src, int src_len, char *dst) {
    cs_base64_encode(src, src_len, dst);
}

int mg_base64_decode(const unsigned char *s, int len, char *dst) {
    return cs_base64_decode(s, len, dst, NULL);
}

#if MG_ENABLE_THREADS
void *mg_start_thread(void *(*f)(void *), void *p) {
#ifdef WINCE
    return (void *)CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)f, p, 0, NULL);
#elif defined(_WIN32)
    return (void *)_beginthread((void(__cdecl *) (void *)) f, 0, p);
#else
    pthread_t thread_id = (pthread_t)0;
    pthread_attr_t attr;

    (void)pthread_attr_init(&attr);
    (void)pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

#if defined(MG_STACK_SIZE) && MG_STACK_SIZE > 1
    (void)pthread_attr_setstacksize(&attr, MG_STACK_SIZE);
#endif

    pthread_create(&thread_id, &attr, f, p);
    pthread_attr_destroy(&attr);

    return (void *)thread_id;
#endif
}
#endif /* MG_ENABLE_THREADS */

/* Set close-on-exec bit for a given socket. */
void mg_set_close_on_exec(sock_t sock) {
#if defined(_WIN32) && !defined(WINCE)
    (void)SetHandleInformation((HANDLE)sock, HANDLE_FLAG_INHERIT, 0);
#elif defined(__unix__)
    fcntl(sock, F_SETFD, FD_CLOEXEC);
#else
    (void)sock;
#endif
}

int mg_sock_addr_to_str(const union socket_address *sa, char *buf, size_t len,
    int flags) {
    int is_v6;
    if (buf == NULL || len <= 0) return 0;
    memset(buf, 0, len);
#if MG_ENABLE_IPV6
    is_v6 = sa->sa.sa_family == AF_INET6;
#else
    is_v6 = 0;
#endif
    if (flags & MG_SOCK_STRINGIFY_IP) {
#if MG_ENABLE_IPV6
        const void *addr = NULL;
        char *start = buf;
        socklen_t capacity = len;
        if (!is_v6) {
            addr = &sa->sin.sin_addr;
        }
        else {
            addr = (void *)&sa->sin6.sin6_addr;
            if (flags & MG_SOCK_STRINGIFY_PORT) {
                *buf = '[';
                start++;
                capacity--;
            }
        }
        if (inet_ntop(sa->sa.sa_family, addr, start, capacity) == NULL) {
            goto cleanup;
        }
#elif defined(_WIN32) || MG_LWIP || (MG_NET_IF == MG_NET_IF_PIC32)
        /* Only Windoze Vista (and newer) have inet_ntop() */
        char *addr_str = inet_ntoa(sa->sin.sin_addr);
        if (addr_str != NULL) {
            strncpy(buf, inet_ntoa(sa->sin.sin_addr), len - 1);
        }
        else {
            goto cleanup;
        }
#else
        if (inet_ntop(AF_INET, (void *)&sa->sin.sin_addr, buf, len) == NULL) {
            goto cleanup;
        }
#endif
    }
    if (flags & MG_SOCK_STRINGIFY_PORT) {
        int port = ntohs(sa->sin.sin_port);
        if (flags & MG_SOCK_STRINGIFY_IP) {
            int buf_len = strlen(buf);
            snprintf(buf + buf_len, len - (buf_len + 1), "%s:%d", (is_v6 ? "]" : ""),
                port);
        }
        else {
            snprintf(buf, len, "%d", port);
        }
    }

    return strlen(buf);

cleanup:
    *buf = '\0';
    return 0;
}

int mg_conn_addr_to_str(struct mg_connection *nc, char *buf, size_t len,
    int flags) {
    union socket_address sa;
    memset(&sa, 0, sizeof(sa));
    mg_if_get_conn_addr(nc, flags & MG_SOCK_STRINGIFY_REMOTE, &sa);
    return mg_sock_addr_to_str(&sa, buf, len, flags);
}

#if MG_ENABLE_HEXDUMP
static int mg_hexdump_n(const void *buf, int len, char *dst, int dst_len,
    int offset) {
    const unsigned char *p = (const unsigned char *)buf;
    char ascii[17] = "";
    int i, idx, n = 0;

    for (i = 0; i < len; i++) {
        idx = i % 16;
        if (idx == 0) {
            if (i > 0) n += snprintf(dst + n, MAX(dst_len - n, 0), "  %s\n", ascii);
            n += snprintf(dst + n, MAX(dst_len - n, 0), "%04x ", i + offset);
        }
        if (dst_len - n < 0) {
            return n;
        }
        n += snprintf(dst + n, MAX(dst_len - n, 0), " %02x", p[i]);
        ascii[idx] = p[i] < 0x20 || p[i] > 0x7e ? '.' : p[i];
        ascii[idx + 1] = '\0';
    }

    while (i++ % 16) n += snprintf(dst + n, MAX(dst_len - n, 0), "%s", "   ");
    n += snprintf(dst + n, MAX(dst_len - n, 0), "  %s\n", ascii);

    return n;
}

int mg_hexdump(const void *buf, int len, char *dst, int dst_len) {
    return mg_hexdump_n(buf, len, dst, dst_len, 0);
}

void mg_hexdumpf(FILE *fp, const void *buf, int len) {
    char tmp[80];
    int offset = 0, n;
    while (len > 0) {
        n = (len < 16 ? len : 16);
        mg_hexdump_n(((const char *)buf) + offset, n, tmp, sizeof(tmp), offset);
        fputs(tmp, fp);
        offset += n;
        len -= n;
    }
}

void mg_hexdump_connection(struct mg_connection *nc, const char *path,
    const void *buf, int num_bytes, int ev) {
    FILE *fp = NULL;
    char src[60], dst[60];
    const char *tag = NULL;
    switch (ev) {
    case MG_EV_RECV:
        tag = "<-";
        break;
    case MG_EV_SEND:
        tag = "->";
        break;
    case MG_EV_ACCEPT:
        tag = "<A";
        break;
    case MG_EV_CONNECT:
        tag = "C>";
        break;
    case MG_EV_CLOSE:
        tag = "XX";
        break;
    }
    if (tag == NULL) return; /* Don't log MG_EV_TIMER, etc */

    if (strcmp(path, "-") == 0) {
        fp = stdout;
    }
    else if (strcmp(path, "--") == 0) {
        fp = stderr;
#if MG_ENABLE_FILESYSTEM
    }
    else {
        fp = mg_fopen(path, "a");
#endif
    }
    if (fp == NULL) return;

    mg_conn_addr_to_str(nc, src, sizeof(src),
        MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
    mg_conn_addr_to_str(nc, dst, sizeof(dst), MG_SOCK_STRINGIFY_IP |
        MG_SOCK_STRINGIFY_PORT |
        MG_SOCK_STRINGIFY_REMOTE);
    fprintf(fp, "%lu %p %s %s %s %d\n", (unsigned long)mg_time(), (void *)nc,
        src, tag, dst, (int)num_bytes);
    if (num_bytes > 0) {
        mg_hexdumpf(fp, buf, num_bytes);
    }
    if (fp != stdout && fp != stderr) fclose(fp);
}
#endif

int mg_is_big_endian(void) {
    static const int n = 1;
    /* TODO(mkm) use compiletime check with 4-byte char literal */
    return ((char *)&n)[0] == 0;
}

DO_NOT_WARN_UNUSED MG_INTERNAL int mg_get_errno(void) {
#ifndef WINCE
    return errno;
#else
    /* TODO(alashkin): translate error codes? */
    return GetLastError();
#endif
}

void mg_mbuf_append_base64_putc(char ch, void *user_data) {
    struct mbuf *mbuf = (struct mbuf *) user_data;
    mbuf_append(mbuf, &ch, sizeof(ch));
}

void mg_mbuf_append_base64(struct mbuf *mbuf, const void *data, size_t len) {
    struct cs_base64_ctx ctx;
    cs_base64_init(&ctx, mg_mbuf_append_base64_putc, mbuf);
    cs_base64_update(&ctx, (const char *)data, len);
    cs_base64_finish(&ctx);
}

void mg_basic_auth_header(const struct mg_str user, const struct mg_str pass,
    struct mbuf *buf) {
    const char *header_prefix = "Authorization: Basic ";
    const char *header_suffix = "\r\n";

    struct cs_base64_ctx ctx;
    cs_base64_init(&ctx, mg_mbuf_append_base64_putc, buf);

    mbuf_append(buf, header_prefix, strlen(header_prefix));

    cs_base64_update(&ctx, user.p, user.len);
    if (pass.len > 0) {
        cs_base64_update(&ctx, ":", 1);
        cs_base64_update(&ctx, pass.p, pass.len);
    }
    cs_base64_finish(&ctx);
    mbuf_append(buf, header_suffix, strlen(header_suffix));
}

struct mg_str mg_url_encode_opt(const struct mg_str src,
    const struct mg_str safe, unsigned int flags) {
    const char *hex =
        (flags & MG_URL_ENCODE_F_UPPERCASE_HEX ? "0123456789ABCDEF"
            : "0123456789abcdef");
    size_t i = 0;
    struct mbuf mb;
    mbuf_init(&mb, src.len);

    for (i = 0; i < src.len; i++) {
        const unsigned char c = *((const unsigned char *)src.p + i);
        if (isalnum(c) || mg_strchr(safe, c) != NULL) {
            mbuf_append(&mb, &c, 1);
        }
        else if (c == ' ' && (flags & MG_URL_ENCODE_F_SPACE_AS_PLUS)) {
            mbuf_append(&mb, "+", 1);
        }
        else {
            mbuf_append(&mb, "%", 1);
            mbuf_append(&mb, &hex[c >> 4], 1);
            mbuf_append(&mb, &hex[c & 15], 1);
        }
    }
    mbuf_append(&mb, "", 1);
    mbuf_trim(&mb);
    return mg_mk_str_n(mb.buf, mb.len - 1);
}

struct mg_str mg_url_encode(const struct mg_str src) {
    return mg_url_encode_opt(src, mg_mk_str("._-$,;~()/"), 0);
}
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_mqtt.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_MQTT

#include <string.h>

 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "mg_mqtt.h" */

static uint16_t getu16(const char *p) {
    const uint8_t *up = (const uint8_t *)p;
    return (up[0] << 8) + up[1];
}

static const char *scanto(const char *p, struct mg_str *s) {
    s->len = getu16(p);
    s->p = p + 2;
    return s->p + s->len;
}

MG_INTERNAL int parse_mqtt(struct mbuf *io, struct mg_mqtt_message *mm) {
    uint8_t header;
    size_t len = 0, len_len = 0;
    const char *p, *end, *eop = &io->buf[io->len];
    unsigned char lc = 0;
    int cmd;

    if (io->len < 2) return MG_MQTT_ERROR_INCOMPLETE_MSG;
    header = io->buf[0];
    cmd = header >> 4;

    /* decode mqtt variable length */
    len = len_len = 0;
    p = io->buf + 1;
    while (p < eop) {
        lc = *((const unsigned char *)p++);
        len += (lc & 0x7f) << 7 * len_len;
        len_len++;
        if (!(lc & 0x80)) break;
        if (len_len > 4) return MG_MQTT_ERROR_MALFORMED_MSG;
    }

    end = p + len;
    if (lc & 0x80 || end > eop) return MG_MQTT_ERROR_INCOMPLETE_MSG;

    mm->cmd = cmd;
    mm->qos = MG_MQTT_GET_QOS(header);

    switch (cmd) {
    case MG_MQTT_CMD_CONNECT: {
        p = scanto(p, &mm->protocol_name);
        if (p > end - 4) return MG_MQTT_ERROR_MALFORMED_MSG;
        mm->protocol_version = *(uint8_t *)p++;
        mm->connect_flags = *(uint8_t *)p++;
        mm->keep_alive_timer = getu16(p);
        p += 2;
        if (p >= end) return MG_MQTT_ERROR_MALFORMED_MSG;
        p = scanto(p, &mm->client_id);
        if (p > end) return MG_MQTT_ERROR_MALFORMED_MSG;
        if (mm->connect_flags & MG_MQTT_HAS_WILL) {
            if (p >= end) return MG_MQTT_ERROR_MALFORMED_MSG;
            p = scanto(p, &mm->will_topic);
        }
        if (mm->connect_flags & MG_MQTT_HAS_WILL) {
            if (p >= end) return MG_MQTT_ERROR_MALFORMED_MSG;
            p = scanto(p, &mm->will_message);
        }
        if (mm->connect_flags & MG_MQTT_HAS_USER_NAME) {
            if (p >= end) return MG_MQTT_ERROR_MALFORMED_MSG;
            p = scanto(p, &mm->user_name);
        }
        if (mm->connect_flags & MG_MQTT_HAS_PASSWORD) {
            if (p >= end) return MG_MQTT_ERROR_MALFORMED_MSG;
            p = scanto(p, &mm->password);
        }
        if (p != end) return MG_MQTT_ERROR_MALFORMED_MSG;

        LOG(LL_DEBUG,
            ("%d %2x %d proto [%.*s] client_id [%.*s] will_topic [%.*s] "
                "will_msg [%.*s] user_name [%.*s] password [%.*s]",
                (int)len, (int)mm->connect_flags, (int)mm->keep_alive_timer,
                (int)mm->protocol_name.len, mm->protocol_name.p,
                (int)mm->client_id.len, mm->client_id.p, (int)mm->will_topic.len,
                mm->will_topic.p, (int)mm->will_message.len, mm->will_message.p,
                (int)mm->user_name.len, mm->user_name.p, (int)mm->password.len,
                mm->password.p));
        break;
    }
    case MG_MQTT_CMD_CONNACK:
        if (end - p < 2) return MG_MQTT_ERROR_MALFORMED_MSG;
        mm->connack_ret_code = p[1];
        break;
    case MG_MQTT_CMD_PUBACK:
    case MG_MQTT_CMD_PUBREC:
    case MG_MQTT_CMD_PUBREL:
    case MG_MQTT_CMD_PUBCOMP:
    case MG_MQTT_CMD_SUBACK:
        if (end - p < 2) return MG_MQTT_ERROR_MALFORMED_MSG;
        mm->message_id = getu16(p);
        p += 2;
        break;
    case MG_MQTT_CMD_PUBLISH: {
        p = scanto(p, &mm->topic);
        if (p > end) return MG_MQTT_ERROR_MALFORMED_MSG;
        if (mm->qos > 0) {
            if (end - p < 2) return MG_MQTT_ERROR_MALFORMED_MSG;
            mm->message_id = getu16(p);
            p += 2;
        }
        mm->payload.p = p;
        mm->payload.len = end - p;
        break;
    }
    case MG_MQTT_CMD_SUBSCRIBE:
        if (end - p < 2) return MG_MQTT_ERROR_MALFORMED_MSG;
        mm->message_id = getu16(p);
        p += 2;
        /*
         * topic expressions are left in the payload and can be parsed with
         * `mg_mqtt_next_subscribe_topic`
         */
        mm->payload.p = p;
        mm->payload.len = end - p;
        break;
    default:
        /* Unhandled command */
        break;
    }

    mm->len = end - io->buf;
    return mm->len;
}

static void mqtt_handler(struct mg_connection *nc, int ev,
    void *ev_data MG_UD_ARG(void *user_data)) {
    struct mbuf *io = &nc->recv_mbuf;
    struct mg_mqtt_message mm;
    memset(&mm, 0, sizeof(mm));

    nc->handler(nc, ev, ev_data MG_UD_ARG(user_data));

    switch (ev) {
    case MG_EV_ACCEPT:
        if (nc->proto_data == NULL) mg_set_protocol_mqtt(nc);
        break;
    case MG_EV_RECV: {
        /* There can be multiple messages in the buffer, process them all. */
        while (1) {
            int len = parse_mqtt(io, &mm);
            if (len < 0) {
                if (len == MG_MQTT_ERROR_MALFORMED_MSG) {
                    /* Protocol error. */
                    nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                }
                else if (len == MG_MQTT_ERROR_INCOMPLETE_MSG) {
                    /* Not fully buffered, let's check if we have a chance to get more
                     * data later */
                    if (nc->recv_mbuf_limit > 0 &&
                        nc->recv_mbuf.len >= nc->recv_mbuf_limit) {
                        LOG(LL_ERROR, ("%p recv buffer (%lu bytes) exceeds the limit "
                            "%lu bytes, and not drained, closing",
                            nc, (unsigned long)nc->recv_mbuf.len,
                            (unsigned long)nc->recv_mbuf_limit));
                        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                    }
                }
                else {
                    /* Should never be here */
                    LOG(LL_ERROR, ("%p invalid len: %d, closing", nc, len));
                    nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                }
                break;
            }

            nc->handler(nc, MG_MQTT_EVENT_BASE + mm.cmd, &mm MG_UD_ARG(user_data));
            mbuf_remove(io, len);
        }
        break;
    }
    case MG_EV_POLL: {
        struct mg_mqtt_proto_data *pd =
            (struct mg_mqtt_proto_data *) nc->proto_data;
        double now = mg_time();
        if (pd->keep_alive > 0 && pd->last_control_time > 0 &&
            (now - pd->last_control_time) > pd->keep_alive) {
            LOG(LL_DEBUG, ("Send PINGREQ"));
            mg_mqtt_ping(nc);
        }
        break;
    }
    }
}

static void mg_mqtt_proto_data_destructor(void *proto_data) {
    MG_FREE(proto_data);
}

static struct mg_str mg_mqtt_next_topic_component(struct mg_str *topic) {
    struct mg_str res = *topic;
    const char *c = mg_strchr(*topic, '/');
    if (c != NULL) {
        res.len = (c - topic->p);
        topic->len -= (res.len + 1);
        topic->p += (res.len + 1);
    }
    else {
        topic->len = 0;
    }
    return res;
}

/* Refernce: https://mosquitto.org/man/mqtt-7.html */
int mg_mqtt_match_topic_expression(struct mg_str exp, struct mg_str topic) {
    struct mg_str ec, tc;
    if (exp.len == 0) return 0;
    while (1) {
        ec = mg_mqtt_next_topic_component(&exp);
        tc = mg_mqtt_next_topic_component(&topic);
        if (ec.len == 0) {
            if (tc.len != 0) return 0;
            if (exp.len == 0) break;
            continue;
        }
        if (mg_vcmp(&ec, "+") == 0) {
            if (tc.len == 0 && topic.len == 0) return 0;
            continue;
        }
        if (mg_vcmp(&ec, "#") == 0) {
            /* Must be the last component in the expression or it's invalid. */
            return (exp.len == 0);
        }
        if (mg_strcmp(ec, tc) != 0) {
            return 0;
        }
    }
    return (tc.len == 0 && topic.len == 0);
}

int mg_mqtt_vmatch_topic_expression(const char *exp, struct mg_str topic) {
    return mg_mqtt_match_topic_expression(mg_mk_str(exp), topic);
}

void mg_set_protocol_mqtt(struct mg_connection *nc) {
    nc->proto_handler = mqtt_handler;
    nc->proto_data = MG_CALLOC(1, sizeof(struct mg_mqtt_proto_data));
    nc->proto_data_destructor = mg_mqtt_proto_data_destructor;
}

static void mg_send_mqtt_header(struct mg_connection *nc, uint8_t cmd,
    uint8_t flags, size_t len) {
    struct mg_mqtt_proto_data *pd = (struct mg_mqtt_proto_data *) nc->proto_data;
    uint8_t buf[1 + sizeof(size_t)];
    uint8_t *vlen = &buf[1];

    buf[0] = (cmd << 4) | flags;

    /* mqtt variable length encoding */
    do {
        *vlen = len % 0x80;
        len /= 0x80;
        if (len > 0) *vlen |= 0x80;
        vlen++;
    } while (len > 0);

    mg_send(nc, buf, vlen - buf);
    pd->last_control_time = mg_time();
}

void mg_send_mqtt_handshake(struct mg_connection *nc, const char *client_id) {
    static struct mg_send_mqtt_handshake_opts opts;
    mg_send_mqtt_handshake_opt(nc, client_id, opts);
}

void mg_send_mqtt_handshake_opt(struct mg_connection *nc, const char *client_id,
    struct mg_send_mqtt_handshake_opts opts) {
    struct mg_mqtt_proto_data *pd = (struct mg_mqtt_proto_data *) nc->proto_data;
    uint16_t id_len = 0, wt_len = 0, wm_len = 0, user_len = 0, pw_len = 0;
    uint16_t netbytes;
    size_t total_len;

    if (client_id != NULL) {
        id_len = strlen(client_id);
    }

    total_len = 7 + 1 + 2 + 2 + id_len;

    if (opts.user_name != NULL) {
        opts.flags |= MG_MQTT_HAS_USER_NAME;
    }
    if (opts.password != NULL) {
        opts.flags |= MG_MQTT_HAS_PASSWORD;
    }
    if (opts.will_topic != NULL && opts.will_message != NULL) {
        wt_len = strlen(opts.will_topic);
        wm_len = strlen(opts.will_message);
        opts.flags |= MG_MQTT_HAS_WILL;
    }
    if (opts.keep_alive == 0) {
        opts.keep_alive = 60;
    }

    if (opts.flags & MG_MQTT_HAS_WILL) {
        total_len += 2 + wt_len + 2 + wm_len;
    }
    if (opts.flags & MG_MQTT_HAS_USER_NAME) {
        user_len = strlen(opts.user_name);
        total_len += 2 + user_len;
    }
    if (opts.flags & MG_MQTT_HAS_PASSWORD) {
        pw_len = strlen(opts.password);
        total_len += 2 + pw_len;
    }

    mg_send_mqtt_header(nc, MG_MQTT_CMD_CONNECT, 0, total_len);
    mg_send(nc, "\00\04MQTT\04", 7);
    mg_send(nc, &opts.flags, 1);

    netbytes = htons(opts.keep_alive);
    mg_send(nc, &netbytes, 2);

    netbytes = htons(id_len);
    mg_send(nc, &netbytes, 2);
    mg_send(nc, client_id, id_len);

    if (opts.flags & MG_MQTT_HAS_WILL) {
        netbytes = htons(wt_len);
        mg_send(nc, &netbytes, 2);
        mg_send(nc, opts.will_topic, wt_len);

        netbytes = htons(wm_len);
        mg_send(nc, &netbytes, 2);
        mg_send(nc, opts.will_message, wm_len);
    }

    if (opts.flags & MG_MQTT_HAS_USER_NAME) {
        netbytes = htons(user_len);
        mg_send(nc, &netbytes, 2);
        mg_send(nc, opts.user_name, user_len);
    }
    if (opts.flags & MG_MQTT_HAS_PASSWORD) {
        netbytes = htons(pw_len);
        mg_send(nc, &netbytes, 2);
        mg_send(nc, opts.password, pw_len);
    }

    if (pd != NULL) {
        pd->keep_alive = opts.keep_alive;
    }
}

void mg_mqtt_publish(struct mg_connection *nc, const char *topic,
    uint16_t message_id, int flags, const void *data,
    size_t len) {
    uint16_t netbytes;
    uint16_t topic_len = strlen(topic);

    size_t total_len = 2 + topic_len + len;
    if (MG_MQTT_GET_QOS(flags) > 0) {
        total_len += 2;
    }

    mg_send_mqtt_header(nc, MG_MQTT_CMD_PUBLISH, flags, total_len);

    netbytes = htons(topic_len);
    mg_send(nc, &netbytes, 2);
    mg_send(nc, topic, topic_len);

    if (MG_MQTT_GET_QOS(flags) > 0) {
        netbytes = htons(message_id);
        mg_send(nc, &netbytes, 2);
    }

    mg_send(nc, data, len);
}

void mg_mqtt_subscribe(struct mg_connection *nc,
    const struct mg_mqtt_topic_expression *topics,
    size_t topics_len, uint16_t message_id) {
    uint16_t netbytes;
    size_t i;
    uint16_t topic_len;
    size_t total_len = 2;

    for (i = 0; i < topics_len; i++) {
        total_len += 2 + strlen(topics[i].topic) + 1;
    }

    mg_send_mqtt_header(nc, MG_MQTT_CMD_SUBSCRIBE, MG_MQTT_QOS(1), total_len);

    netbytes = htons(message_id);
    mg_send(nc, (char *)&netbytes, 2);

    for (i = 0; i < topics_len; i++) {
        topic_len = strlen(topics[i].topic);
        netbytes = htons(topic_len);
        mg_send(nc, &netbytes, 2);
        mg_send(nc, topics[i].topic, topic_len);
        mg_send(nc, &topics[i].qos, 1);
    }
}

int mg_mqtt_next_subscribe_topic(struct mg_mqtt_message *msg,
    struct mg_str *topic, uint8_t *qos, int pos) {
    unsigned char *buf = (unsigned char *)msg->payload.p + pos;
    int new_pos;

    if ((size_t)pos >= msg->payload.len) return -1;

    topic->len = buf[0] << 8 | buf[1];
    topic->p = (char *)buf + 2;
    new_pos = pos + 2 + topic->len + 1;
    if ((size_t)new_pos > msg->payload.len) return -1;
    *qos = buf[2 + topic->len];
    return new_pos;
}

void mg_mqtt_unsubscribe(struct mg_connection *nc, char **topics,
    size_t topics_len, uint16_t message_id) {
    uint16_t netbytes;
    size_t i;
    uint16_t topic_len;
    size_t total_len = 2;

    for (i = 0; i < topics_len; i++) {
        total_len += 2 + strlen(topics[i]);
    }

    mg_send_mqtt_header(nc, MG_MQTT_CMD_UNSUBSCRIBE, MG_MQTT_QOS(1), total_len);

    netbytes = htons(message_id);
    mg_send(nc, (char *)&netbytes, 2);

    for (i = 0; i < topics_len; i++) {
        topic_len = strlen(topics[i]);
        netbytes = htons(topic_len);
        mg_send(nc, &netbytes, 2);
        mg_send(nc, topics[i], topic_len);
    }
}

void mg_mqtt_connack(struct mg_connection *nc, uint8_t return_code) {
    uint8_t unused = 0;
    mg_send_mqtt_header(nc, MG_MQTT_CMD_CONNACK, 0, 2);
    mg_send(nc, &unused, 1);
    mg_send(nc, &return_code, 1);
}

/*
 * Sends a command which contains only a `message_id` and a QoS level of 1.
 *
 * Helper function.
 */
static void mg_send_mqtt_short_command(struct mg_connection *nc, uint8_t cmd,
    uint16_t message_id) {
    uint16_t netbytes;
    uint8_t flags = (cmd == MG_MQTT_CMD_PUBREL ? 2 : 0);

    mg_send_mqtt_header(nc, cmd, flags, 2 /* len */);

    netbytes = htons(message_id);
    mg_send(nc, &netbytes, 2);
}

void mg_mqtt_puback(struct mg_connection *nc, uint16_t message_id) {
    mg_send_mqtt_short_command(nc, MG_MQTT_CMD_PUBACK, message_id);
}

void mg_mqtt_pubrec(struct mg_connection *nc, uint16_t message_id) {
    mg_send_mqtt_short_command(nc, MG_MQTT_CMD_PUBREC, message_id);
}

void mg_mqtt_pubrel(struct mg_connection *nc, uint16_t message_id) {
    mg_send_mqtt_short_command(nc, MG_MQTT_CMD_PUBREL, message_id);
}

void mg_mqtt_pubcomp(struct mg_connection *nc, uint16_t message_id) {
    mg_send_mqtt_short_command(nc, MG_MQTT_CMD_PUBCOMP, message_id);
}

void mg_mqtt_suback(struct mg_connection *nc, uint8_t *qoss, size_t qoss_len,
    uint16_t message_id) {
    size_t i;
    uint16_t netbytes;

    mg_send_mqtt_header(nc, MG_MQTT_CMD_SUBACK, MG_MQTT_QOS(1), 2 + qoss_len);

    netbytes = htons(message_id);
    mg_send(nc, &netbytes, 2);

    for (i = 0; i < qoss_len; i++) {
        mg_send(nc, &qoss[i], 1);
    }
}

void mg_mqtt_unsuback(struct mg_connection *nc, uint16_t message_id) {
    mg_send_mqtt_short_command(nc, MG_MQTT_CMD_UNSUBACK, message_id);
}

void mg_mqtt_ping(struct mg_connection *nc) {
    mg_send_mqtt_header(nc, MG_MQTT_CMD_PINGREQ, 0, 0);
}

void mg_mqtt_pong(struct mg_connection *nc) {
    mg_send_mqtt_header(nc, MG_MQTT_CMD_PINGRESP, 0, 0);
}

void mg_mqtt_disconnect(struct mg_connection *nc) {
    mg_send_mqtt_header(nc, MG_MQTT_CMD_DISCONNECT, 0, 0);
}

#endif /* MG_ENABLE_MQTT */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_mqtt_server.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "mg_mqtt_server.h" */

#if MG_ENABLE_MQTT_BROKER

static void mg_mqtt_session_init(struct mg_mqtt_broker *brk,
    struct mg_mqtt_session *s,
    struct mg_connection *nc) {
    s->brk = brk;
    s->subscriptions = NULL;
    s->num_subscriptions = 0;
    s->nc = nc;
}

static void mg_mqtt_add_session(struct mg_mqtt_session *s) {
    LIST_INSERT_HEAD(&s->brk->sessions, s, link);
}

static void mg_mqtt_remove_session(struct mg_mqtt_session *s) {
    LIST_REMOVE(s, link);
}

static void mg_mqtt_destroy_session(struct mg_mqtt_session *s) {
    size_t i;
    for (i = 0; i < s->num_subscriptions; i++) {
        MG_FREE((void *)s->subscriptions[i].topic);
    }
    MG_FREE(s->subscriptions);
    MG_FREE(s);
}

static void mg_mqtt_close_session(struct mg_mqtt_session *s) {
    mg_mqtt_remove_session(s);
    mg_mqtt_destroy_session(s);
}

void mg_mqtt_broker_init(struct mg_mqtt_broker *brk, void *user_data) {
    LIST_INIT(&brk->sessions);
    brk->user_data = user_data;
}

static void mg_mqtt_broker_handle_connect(struct mg_mqtt_broker *brk,
    struct mg_connection *nc) {
    struct mg_mqtt_session *s =
        (struct mg_mqtt_session *) MG_CALLOC(1, sizeof *s);
    if (s == NULL) {
        /* LCOV_EXCL_START */
        mg_mqtt_connack(nc, MG_EV_MQTT_CONNACK_SERVER_UNAVAILABLE);
        return;
        /* LCOV_EXCL_STOP */
    }

    /* TODO(mkm): check header (magic and version) */

    mg_mqtt_session_init(brk, s, nc);
    nc->priv_2 = s;
    mg_mqtt_add_session(s);

    mg_mqtt_connack(nc, MG_EV_MQTT_CONNACK_ACCEPTED);
}

static void mg_mqtt_broker_handle_subscribe(struct mg_connection *nc,
    struct mg_mqtt_message *msg) {
    struct mg_mqtt_session *ss = (struct mg_mqtt_session *) nc->priv_2;
    uint8_t qoss[MG_MQTT_MAX_SESSION_SUBSCRIPTIONS];
    size_t num_subs = 0;
    struct mg_str topic;
    uint8_t qos;
    int pos;
    struct mg_mqtt_topic_expression *te;

    for (pos = 0;
        (pos = mg_mqtt_next_subscribe_topic(msg, &topic, &qos, pos)) != -1;) {
        if (num_subs >= sizeof(MG_MQTT_MAX_SESSION_SUBSCRIPTIONS) ||
            (ss->num_subscriptions + num_subs >=
                MG_MQTT_MAX_SESSION_SUBSCRIPTIONS)) {
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
            return;
        }
        qoss[num_subs++] = qos;
    }

    if (num_subs > 0) {
        te = (struct mg_mqtt_topic_expression *) MG_REALLOC(
            ss->subscriptions,
            sizeof(*ss->subscriptions) * (ss->num_subscriptions + num_subs));
        if (te == NULL) {
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
            return;
        }
        ss->subscriptions = te;
        for (pos = 0;
            pos < (int)msg->payload.len &&
            (pos = mg_mqtt_next_subscribe_topic(msg, &topic, &qos, pos)) != -1;
            ss->num_subscriptions++) {
            te = &ss->subscriptions[ss->num_subscriptions];
            te->topic = (char *)MG_MALLOC(topic.len + 1);
            te->qos = qos;
            memcpy((char *)te->topic, topic.p, topic.len);
            ((char *)te->topic)[topic.len] = '\0';
        }
    }

    if (pos == (int)msg->payload.len) {
        mg_mqtt_suback(nc, qoss, num_subs, msg->message_id);
    }
    else {
        /* We did not fully parse the payload, something must be wrong. */
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
    }
}

static void mg_mqtt_broker_handle_publish(struct mg_mqtt_broker *brk,
    struct mg_mqtt_message *msg) {
    struct mg_mqtt_session *s;
    size_t i;

    for (s = mg_mqtt_next(brk, NULL); s != NULL; s = mg_mqtt_next(brk, s)) {
        for (i = 0; i < s->num_subscriptions; i++) {
            if (mg_mqtt_vmatch_topic_expression(s->subscriptions[i].topic,
                msg->topic)) {
                char buf[100], *p = buf;
                mg_asprintf(&p, sizeof(buf), "%.*s", (int)msg->topic.len,
                    msg->topic.p);
                if (p == NULL) {
                    return;
                }
                mg_mqtt_publish(s->nc, p, 0, 0, msg->payload.p, msg->payload.len);
                if (p != buf) {
                    MG_FREE(p);
                }
                break;
            }
        }
    }
}

void mg_mqtt_broker(struct mg_connection *nc, int ev, void *data) {
    struct mg_mqtt_message *msg = (struct mg_mqtt_message *) data;
    struct mg_mqtt_broker *brk;

    if (nc->listener) {
        brk = (struct mg_mqtt_broker *) nc->listener->priv_2;
    }
    else {
        brk = (struct mg_mqtt_broker *) nc->priv_2;
    }

    switch (ev) {
    case MG_EV_ACCEPT:
        if (nc->proto_data == NULL) mg_set_protocol_mqtt(nc);
        nc->priv_2 = NULL; /* Clear up the inherited pointer to broker */
        break;
    case MG_EV_MQTT_CONNECT:
        if (nc->priv_2 == NULL) {
            mg_mqtt_broker_handle_connect(brk, nc);
        }
        else {
            /* Repeated CONNECT */
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        }
        break;
    case MG_EV_MQTT_SUBSCRIBE:
        if (nc->priv_2 != NULL) {
            mg_mqtt_broker_handle_subscribe(nc, msg);
        }
        else {
            /* Subscribe before CONNECT */
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        }
        break;
    case MG_EV_MQTT_PUBLISH:
        if (nc->priv_2 != NULL) {
            mg_mqtt_broker_handle_publish(brk, msg);
        }
        else {
            /* Publish before CONNECT */
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        }
        break;
    case MG_EV_CLOSE:
        if (nc->listener && nc->priv_2 != NULL) {
            mg_mqtt_close_session((struct mg_mqtt_session *) nc->priv_2);
        }
        break;
    }
}

struct mg_mqtt_session *mg_mqtt_next(struct mg_mqtt_broker *brk,
    struct mg_mqtt_session *s) {
    return s == NULL ? LIST_FIRST(&brk->sessions) : LIST_NEXT(s, link);
}

#endif /* MG_ENABLE_MQTT_BROKER */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_dns.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_DNS

 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "mg_dns.h" */

static int mg_dns_tid = 0xa0;

struct mg_dns_header {
    uint16_t transaction_id;
    uint16_t flags;
    uint16_t num_questions;
    uint16_t num_answers;
    uint16_t num_authority_prs;
    uint16_t num_other_prs;
};

struct mg_dns_resource_record *mg_dns_next_record(
    struct mg_dns_message *msg, int query,
    struct mg_dns_resource_record *prev) {
    struct mg_dns_resource_record *rr;

    for (rr = (prev == NULL ? msg->answers : prev + 1);
        rr - msg->answers < msg->num_answers; rr++) {
        if (rr->rtype == query) {
            return rr;
        }
    }
    return NULL;
}

int mg_dns_parse_record_data(struct mg_dns_message *msg,
    struct mg_dns_resource_record *rr, void *data,
    size_t data_len) {
    switch (rr->rtype) {
    case MG_DNS_A_RECORD:
        if (data_len < sizeof(struct in_addr)) {
            return -1;
        }
        if (rr->rdata.p + data_len > msg->pkt.p + msg->pkt.len) {
            return -1;
        }
        memcpy(data, rr->rdata.p, data_len);
        return 0;
#if MG_ENABLE_IPV6
    case MG_DNS_AAAA_RECORD:
        if (data_len < sizeof(struct in6_addr)) {
            return -1; /* LCOV_EXCL_LINE */
        }
        memcpy(data, rr->rdata.p, data_len);
        return 0;
#endif
    case MG_DNS_CNAME_RECORD:
        mg_dns_uncompress_name(msg, &rr->rdata, (char *)data, data_len);
        return 0;
    }

    return -1;
}

int mg_dns_insert_header(struct mbuf *io, size_t pos,
    struct mg_dns_message *msg) {
    struct mg_dns_header header;

    memset(&header, 0, sizeof(header));
    header.transaction_id = msg->transaction_id;
    header.flags = htons(msg->flags);
    header.num_questions = htons(msg->num_questions);
    header.num_answers = htons(msg->num_answers);

    return mbuf_insert(io, pos, &header, sizeof(header));
}

int mg_dns_copy_questions(struct mbuf *io, struct mg_dns_message *msg) {
    unsigned char *begin, *end;
    struct mg_dns_resource_record *last_q;
    if (msg->num_questions <= 0) return 0;
    begin = (unsigned char *)msg->pkt.p + sizeof(struct mg_dns_header);
    last_q = &msg->questions[msg->num_questions - 1];
    end = (unsigned char *)last_q->name.p + last_q->name.len + 4;
    return mbuf_append(io, begin, end - begin);
}

int mg_dns_encode_name(struct mbuf *io, const char *name, size_t len) {
    const char *s;
    unsigned char n;
    size_t pos = io->len;

    do {
        if ((s = strchr(name, '.')) == NULL) {
            s = name + len;
        }

        if (s - name > 127) {
            return -1; /* TODO(mkm) cover */
        }
        n = s - name;           /* chunk length */
        mbuf_append(io, &n, 1); /* send length */
        mbuf_append(io, name, n);

        if (*s == '.') {
            n++;
        }

        name += n;
        len -= n;
    } while (*s != '\0');
    mbuf_append(io, "\0", 1); /* Mark end of host name */

    return io->len - pos;
}

int mg_dns_encode_record(struct mbuf *io, struct mg_dns_resource_record *rr,
    const char *name, size_t nlen, const void *rdata,
    size_t rlen) {
    size_t pos = io->len;
    uint16_t u16;
    uint32_t u32;

    if (rr->kind == MG_DNS_INVALID_RECORD) {
        return -1; /* LCOV_EXCL_LINE */
    }

    if (mg_dns_encode_name(io, name, nlen) == -1) {
        return -1;
    }

    u16 = htons(rr->rtype);
    mbuf_append(io, &u16, 2);
    u16 = htons(rr->rclass);
    mbuf_append(io, &u16, 2);

    if (rr->kind == MG_DNS_ANSWER) {
        u32 = htonl(rr->ttl);
        mbuf_append(io, &u32, 4);

        if (rr->rtype == MG_DNS_CNAME_RECORD) {
            int clen;
            /* fill size after encoding */
            size_t off = io->len;
            mbuf_append(io, &u16, 2);
            if ((clen = mg_dns_encode_name(io, (const char *)rdata, rlen)) == -1) {
                return -1;
            }
            u16 = clen;
            io->buf[off] = u16 >> 8;
            io->buf[off + 1] = u16 & 0xff;
        }
        else {
            u16 = htons((uint16_t)rlen);
            mbuf_append(io, &u16, 2);
            mbuf_append(io, rdata, rlen);
        }
    }

    return io->len - pos;
}

void mg_send_dns_query(struct mg_connection *nc, const char *name,
    int query_type) {
    struct mg_dns_message *msg =
        (struct mg_dns_message *) MG_CALLOC(1, sizeof(*msg));
    struct mbuf pkt;
    struct mg_dns_resource_record *rr = &msg->questions[0];

    DBG(("%s %d", name, query_type));

    mbuf_init(&pkt, 64 /* Start small, it'll grow as needed. */);

    msg->transaction_id = ++mg_dns_tid;
    msg->flags = 0x100;
    msg->num_questions = 1;

    mg_dns_insert_header(&pkt, 0, msg);

    rr->rtype = query_type;
    rr->rclass = 1; /* Class: inet */
    rr->kind = MG_DNS_QUESTION;

    if (mg_dns_encode_record(&pkt, rr, name, strlen(name), NULL, 0) == -1) {
        /* TODO(mkm): return an error code */
        goto cleanup; /* LCOV_EXCL_LINE */
    }

    /* TCP DNS requires messages to be prefixed with len */
    if (!(nc->flags & MG_F_UDP)) {
        uint16_t len = htons((uint16_t)pkt.len);
        mbuf_insert(&pkt, 0, &len, 2);
    }

    mg_send(nc, pkt.buf, pkt.len);
    mbuf_free(&pkt);

cleanup:
    MG_FREE(msg);
}

static unsigned char *mg_parse_dns_resource_record(
    unsigned char *data, unsigned char *end, struct mg_dns_resource_record *rr,
    int reply) {
    unsigned char *name = data;
    int chunk_len, data_len;

    while (data < end && (chunk_len = *data)) {
        if (((unsigned char *)data)[0] & 0xc0) {
            data += 1;
            break;
        }
        data += chunk_len + 1;
    }

    if (data > end - 5) {
        return NULL;
    }

    rr->name.p = (char *)name;
    rr->name.len = data - name + 1;
    data++;

    rr->rtype = data[0] << 8 | data[1];
    data += 2;

    rr->rclass = data[0] << 8 | data[1];
    data += 2;

    rr->kind = reply ? MG_DNS_ANSWER : MG_DNS_QUESTION;
    if (reply) {
        if (data >= end - 6) {
            return NULL;
        }

        rr->ttl = (uint32_t)data[0] << 24 | (uint32_t)data[1] << 16 |
            data[2] << 8 | data[3];
        data += 4;

        data_len = *data << 8 | *(data + 1);
        data += 2;

        rr->rdata.p = (char *)data;
        rr->rdata.len = data_len;
        data += data_len;
    }
    return data;
}

int mg_parse_dns(const char *buf, int len, struct mg_dns_message *msg) {
    struct mg_dns_header *header = (struct mg_dns_header *) buf;
    unsigned char *data = (unsigned char *)buf + sizeof(*header);
    unsigned char *end = (unsigned char *)buf + len;
    int i;

    memset(msg, 0, sizeof(*msg));
    msg->pkt.p = buf;
    msg->pkt.len = len;

    if (len < (int) sizeof(*header)) return -1;

    msg->transaction_id = header->transaction_id;
    msg->flags = ntohs(header->flags);
    msg->num_questions = ntohs(header->num_questions);
    if (msg->num_questions > (int) ARRAY_SIZE(msg->questions)) {
        msg->num_questions = (int)ARRAY_SIZE(msg->questions);
    }
    msg->num_answers = ntohs(header->num_answers);
    if (msg->num_answers > (int)ARRAY_SIZE(msg->answers)) {
        msg->num_answers = (int)ARRAY_SIZE(msg->answers);
    }

    for (i = 0; i < msg->num_questions; i++) {
        data = mg_parse_dns_resource_record(data, end, &msg->questions[i], 0);
        if (data == NULL) return -1;
    }

    for (i = 0; i < msg->num_answers; i++) {
        data = mg_parse_dns_resource_record(data, end, &msg->answers[i], 1);
        if (data == NULL) return -1;
    }

    return 0;
}

size_t mg_dns_uncompress_name(struct mg_dns_message *msg, struct mg_str *name,
    char *dst, int dst_len) {
    int chunk_len, num_ptrs = 0;
    char *old_dst = dst;
    const unsigned char *data = (unsigned char *)name->p;
    const unsigned char *end = (unsigned char *)msg->pkt.p + msg->pkt.len;

    if (data >= end) {
        return 0;
    }

    while ((chunk_len = *data++)) {
        int leeway = dst_len - (dst - old_dst);
        if (data >= end) {
            return 0;
        }

        if ((chunk_len & 0xc0) == 0xc0) {
            uint16_t off = (data[-1] & (~0xc0)) << 8 | data[0];
            if (off >= msg->pkt.len) {
                return 0;
            }
            /* Basic circular loop avoidance: allow up to 16 pointer hops. */
            if (++num_ptrs > 15) {
                return 0;
            }
            data = (unsigned char *)msg->pkt.p + off;
            continue;
        }
        if (chunk_len > 63) {
            return 0;
        }
        if (chunk_len > leeway) {
            chunk_len = leeway;
        }

        if (data + chunk_len >= end) {
            return 0;
        }

        memcpy(dst, data, chunk_len);
        data += chunk_len;
        dst += chunk_len;
        leeway -= chunk_len;
        if (leeway == 0) {
            return dst - old_dst;
        }
        *dst++ = '.';
    }

    if (dst != old_dst) {
        *--dst = 0;
    }
    return dst - old_dst;
}

static void dns_handler(struct mg_connection *nc, int ev,
    void *ev_data MG_UD_ARG(void *user_data)) {
    struct mbuf *io = &nc->recv_mbuf;
    struct mg_dns_message msg;

    /* Pass low-level events to the user handler */
    nc->handler(nc, ev, ev_data MG_UD_ARG(user_data));

    switch (ev) {
    case MG_EV_RECV:
        if (!(nc->flags & MG_F_UDP)) {
            mbuf_remove(&nc->recv_mbuf, 2);
        }
        if (mg_parse_dns(nc->recv_mbuf.buf, nc->recv_mbuf.len, &msg) == -1) {
            /* reply + recursion allowed + format error */
            memset(&msg, 0, sizeof(msg));
            msg.flags = 0x8081;
            mg_dns_insert_header(io, 0, &msg);
            if (!(nc->flags & MG_F_UDP)) {
                uint16_t len = htons((uint16_t)io->len);
                mbuf_insert(io, 0, &len, 2);
            }
            mg_send(nc, io->buf, io->len);
        }
        else {
            /* Call user handler with parsed message */
            nc->handler(nc, MG_DNS_MESSAGE, &msg MG_UD_ARG(user_data));
        }
        mbuf_remove(io, io->len);
        break;
    }
}

void mg_set_protocol_dns(struct mg_connection *nc) {
    nc->proto_handler = dns_handler;
}

#endif /* MG_ENABLE_DNS */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_dns_server.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_DNS_SERVER

 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "dns-server.h" */

struct mg_dns_reply mg_dns_create_reply(struct mbuf *io,
    struct mg_dns_message *msg) {
    struct mg_dns_reply rep;
    rep.msg = msg;
    rep.io = io;
    rep.start = io->len;

    /* reply + recursion allowed */
    msg->flags |= 0x8080;
    mg_dns_copy_questions(io, msg);

    msg->num_answers = 0;
    return rep;
}

void mg_dns_send_reply(struct mg_connection *nc, struct mg_dns_reply *r) {
    size_t sent = r->io->len - r->start;
    mg_dns_insert_header(r->io, r->start, r->msg);
    if (!(nc->flags & MG_F_UDP)) {
        uint16_t len = htons((uint16_t)sent);
        mbuf_insert(r->io, r->start, &len, 2);
    }

    if (&nc->send_mbuf != r->io) {
        mg_send(nc, r->io->buf + r->start, r->io->len - r->start);
        r->io->len = r->start;
    }
}

int mg_dns_reply_record(struct mg_dns_reply *reply,
    struct mg_dns_resource_record *question,
    const char *name, int rtype, int ttl, const void *rdata,
    size_t rdata_len) {
    struct mg_dns_message *msg = (struct mg_dns_message *) reply->msg;
    char rname[512];
    struct mg_dns_resource_record *ans = &msg->answers[msg->num_answers];
    if (msg->num_answers >= MG_MAX_DNS_ANSWERS) {
        return -1; /* LCOV_EXCL_LINE */
    }

    if (name == NULL) {
        name = rname;
        rname[511] = 0;
        mg_dns_uncompress_name(msg, &question->name, rname, sizeof(rname) - 1);
    }

    *ans = *question;
    ans->kind = MG_DNS_ANSWER;
    ans->rtype = rtype;
    ans->ttl = ttl;

    if (mg_dns_encode_record(reply->io, ans, name, strlen(name), rdata,
        rdata_len) == -1) {
        return -1; /* LCOV_EXCL_LINE */
    };

    msg->num_answers++;
    return 0;
}

#endif /* MG_ENABLE_DNS_SERVER */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_resolv.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_ASYNC_RESOLVER

 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "mg_resolv.h" */

#ifndef MG_DEFAULT_NAMESERVER
#define MG_DEFAULT_NAMESERVER "8.8.8.8"
#endif

struct mg_resolve_async_request {
    char name[1024];
    int query;
    mg_resolve_callback_t callback;
    void *data;
    time_t timeout;
    int max_retries;
    enum mg_resolve_err err;

    /* state */
    time_t last_time;
    int retries;
};

/*
 * Find what nameserver to use.
 *
 * Return 0 if OK, -1 if error
 */
static int mg_get_ip_address_of_nameserver(char *name, size_t name_len) {
    int ret = -1;

#ifdef _WIN32
    int i;
    LONG err;
    HKEY hKey, hSub;
    wchar_t subkey[512], value[128],
        *key = L"SYSTEM\\ControlSet001\\Services\\Tcpip\\Parameters\\Interfaces";

    if ((err = RegOpenKeyExW(HKEY_LOCAL_MACHINE, key, 0, KEY_READ, &hKey)) !=
        ERROR_SUCCESS) {
        fprintf(stderr, "cannot open reg key %S: %ld\n", key, err);
        ret = -1;
    }
    else {
        for (ret = -1, i = 0; 1; i++) {
            DWORD subkey_size = sizeof(subkey), type, len = sizeof(value);
            if (RegEnumKeyExW(hKey, i, subkey, &subkey_size, NULL, NULL, NULL,
                NULL) != ERROR_SUCCESS) {
                break;
            }
            if (RegOpenKeyExW(hKey, subkey, 0, KEY_READ, &hSub) == ERROR_SUCCESS &&
                ((RegQueryValueExW(hSub, L"NameServer", 0, &type, (void *)value,
                    &len) == ERROR_SUCCESS &&
                    value[0] != '\0') ||
                    (RegQueryValueExW(hSub, L"DhcpNameServer", 0, &type, (void *)value,
                        &len) == ERROR_SUCCESS &&
                        value[0] != '\0'))) {
                /*
                 * See https://github.com/cesanta/mongoose/issues/176
                 * The value taken from the registry can be empty, a single
                 * IP address, or multiple IP addresses separated by comma.
                 * If it's empty, check the next interface.
                 * If it's multiple IP addresses, take the first one.
                 */
                wchar_t *comma = wcschr(value, ',');
                if (comma != NULL) {
                    *comma = '\0';
                }
                /* %S will convert wchar_t -> char */
                snprintf(name, name_len, "%S", value);
                ret = 0;
                RegCloseKey(hSub);
                break;
            }
        }
        RegCloseKey(hKey);
    }
#elif MG_ENABLE_FILESYSTEM && defined(MG_RESOLV_CONF_FILE_NAME)
    FILE *fp;
    char line[512];

    if ((fp = mg_fopen(MG_RESOLV_CONF_FILE_NAME, "r")) == NULL) {
        ret = -1;
    }
    else {
        /* Try to figure out what nameserver to use */
        for (ret = -1; fgets(line, sizeof(line), fp) != NULL;) {
            unsigned int a, b, c, d;
            if (sscanf(line, "nameserver %u.%u.%u.%u", &a, &b, &c, &d) == 4) {
                snprintf(name, name_len, "%u.%u.%u.%u", a, b, c, d);
                ret = 0;
                break;
            }
        }
        (void)fclose(fp);
    }
#else
    snprintf(name, name_len, "%s", MG_DEFAULT_NAMESERVER);
#endif /* _WIN32 */

    return ret;
}

int mg_resolve_from_hosts_file(const char *name, union socket_address *usa) {
#if MG_ENABLE_FILESYSTEM && defined(MG_HOSTS_FILE_NAME)
    /* TODO(mkm) cache /etc/hosts */
    FILE *fp;
    char line[1024];
    char *p;
    char alias[256];
    unsigned int a, b, c, d;
    int len = 0;

    if ((fp = mg_fopen(MG_HOSTS_FILE_NAME, "r")) == NULL) {
        return -1;
    }

    for (; fgets(line, sizeof(line), fp) != NULL;) {
        if (line[0] == '#') continue;

        if (sscanf(line, "%u.%u.%u.%u%n", &a, &b, &c, &d, &len) == 0) {
            /* TODO(mkm): handle ipv6 */
            continue;
        }
        for (p = line + len; sscanf(p, "%s%n", alias, &len) == 1; p += len) {
            if (strcmp(alias, name) == 0) {
                usa->sin.sin_addr.s_addr = htonl(a << 24 | b << 16 | c << 8 | d);
                fclose(fp);
                return 0;
            }
        }
    }

    fclose(fp);
#else
    (void)name;
    (void)usa;
#endif

    return -1;
}

static void mg_resolve_async_eh(struct mg_connection *nc, int ev,
    void *data MG_UD_ARG(void *user_data)) {
    time_t now = (time_t)mg_time();
    struct mg_resolve_async_request *req;
    struct mg_dns_message *msg;
#if !MG_ENABLE_CALLBACK_USERDATA
    void *user_data = nc->user_data;
#endif

    if (ev != MG_EV_POLL) {
        DBG(("ev=%d user_data=%p", ev, user_data));
    }

    req = (struct mg_resolve_async_request *) user_data;

    if (req == NULL) {
        return;
    }

    switch (ev) {
    case MG_EV_POLL:
        if (req->retries > req->max_retries) {
            req->err = MG_RESOLVE_EXCEEDED_RETRY_COUNT;
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
            break;
        }
        if (nc->flags & MG_F_CONNECTING) break;
        /* fallthrough */
    case MG_EV_CONNECT:
        if (req->retries == 0 || now - req->last_time >= req->timeout) {
            mg_send_dns_query(nc, req->name, req->query);
            req->last_time = now;
            req->retries++;
        }
        break;
    case MG_EV_RECV:
        msg = (struct mg_dns_message *) MG_MALLOC(sizeof(*msg));
        if (mg_parse_dns(nc->recv_mbuf.buf, *(int *)data, msg) == 0 &&
            msg->num_answers > 0) {
            req->callback(msg, req->data, MG_RESOLVE_OK);
            nc->user_data = NULL;
            MG_FREE(req);
        }
        else {
            req->err = MG_RESOLVE_NO_ANSWERS;
        }
        MG_FREE(msg);
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        break;
    case MG_EV_SEND:
        /*
         * If a send error occurs, prevent closing of the connection by the core.
         * We will retry after timeout.
         */
        nc->flags &= ~MG_F_CLOSE_IMMEDIATELY;
        mbuf_remove(&nc->send_mbuf, nc->send_mbuf.len);
        break;
    case MG_EV_TIMER:
        req->err = MG_RESOLVE_TIMEOUT;
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
        break;
    case MG_EV_CLOSE:
        /* If we got here with request still not done, fire an error callback. */
        if (req != NULL) {
            char addr[32];
            mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr), MG_SOCK_STRINGIFY_IP);
#ifdef MG_LOG_DNS_FAILURES
            LOG(LL_ERROR, ("Failed to resolve '%s', server %s", req->name, addr));
#endif
            req->callback(NULL, req->data, req->err);
            nc->user_data = NULL;
            MG_FREE(req);
        }
        break;
    }
}

int mg_resolve_async(struct mg_mgr *mgr, const char *name, int query,
    mg_resolve_callback_t cb, void *data) {
    struct mg_resolve_async_opts opts;
    memset(&opts, 0, sizeof(opts));
    return mg_resolve_async_opt(mgr, name, query, cb, data, opts);
}

int mg_resolve_async_opt(struct mg_mgr *mgr, const char *name, int query,
    mg_resolve_callback_t cb, void *data,
    struct mg_resolve_async_opts opts) {
    struct mg_resolve_async_request *req;
    struct mg_connection *dns_nc;
    const char *nameserver = opts.nameserver;
    char dns_server_buff[17], nameserver_url[26];

    if (nameserver == NULL) {
        nameserver = mgr->nameserver;
    }

    DBG(("%s %d %p", name, query, opts.dns_conn));

    /* resolve with DNS */
    req = (struct mg_resolve_async_request *) MG_CALLOC(1, sizeof(*req));
    if (req == NULL) {
        return -1;
    }

    strncpy(req->name, name, sizeof(req->name));
    req->name[sizeof(req->name) - 1] = '\0';

    req->query = query;
    req->callback = cb;
    req->data = data;
    /* TODO(mkm): parse defaults out of resolve.conf */
    req->max_retries = opts.max_retries ? opts.max_retries : 2;
    req->timeout = opts.timeout ? opts.timeout : 5;

    /* Lazily initialize dns server */
    if (nameserver == NULL) {
        if (mg_get_ip_address_of_nameserver(dns_server_buff,
            sizeof(dns_server_buff)) != -1) {
            nameserver = dns_server_buff;
        }
        else {
            nameserver = MG_DEFAULT_NAMESERVER;
        }
    }

    snprintf(nameserver_url, sizeof(nameserver_url), "udp://%s:53", nameserver);

    dns_nc = mg_connect(mgr, nameserver_url, MG_CB(mg_resolve_async_eh, NULL));
    if (dns_nc == NULL) {
        MG_FREE(req);
        return -1;
    }
    dns_nc->user_data = req;
    if (opts.dns_conn != NULL) {
        *opts.dns_conn = dns_nc;
    }

    return 0;
}

void mg_set_nameserver(struct mg_mgr *mgr, const char *nameserver) {
    MG_FREE((char *)mgr->nameserver);
    mgr->nameserver = NULL;
    if (nameserver != NULL) {
        mgr->nameserver = strdup(nameserver);
    }
}

#endif /* MG_ENABLE_ASYNC_RESOLVER */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_coap.c"
#endif
/*
 * Copyright (c) 2015 Cesanta Software Limited
 * All rights reserved
 * This software is dual-licensed: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. For the terms of this
 * license, see <http://www.gnu.org/licenses/>.
 *
 * You are free to use this software under the terms of the GNU General
 * Public License, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * Alternatively, you can license this software under a commercial
 * license, as set out in <https://www.cesanta.com/license>.
 */

 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "mg_coap.h" */

#if MG_ENABLE_COAP

void mg_coap_free_options(struct mg_coap_message *cm) {
    while (cm->options != NULL) {
        struct mg_coap_option *next = cm->options->next;
        MG_FREE(cm->options);
        cm->options = next;
    }
}

struct mg_coap_option *mg_coap_add_option(struct mg_coap_message *cm,
    uint32_t number, char *value,
    size_t len) {
    struct mg_coap_option *new_option =
        (struct mg_coap_option *) MG_CALLOC(1, sizeof(*new_option));

    new_option->number = number;
    new_option->value.p = value;
    new_option->value.len = len;

    if (cm->options == NULL) {
        cm->options = cm->optiomg_tail = new_option;
    }
    else {
        /*
         * A very simple attention to help clients to compose options:
         * CoAP wants to see options ASC ordered.
         * Could be change by using sort in coap_compose
         */
        if (cm->optiomg_tail->number <= new_option->number) {
            /* if option is already ordered just add it */
            cm->optiomg_tail = cm->optiomg_tail->next = new_option;
        }
        else {
            /* looking for appropriate position */
            struct mg_coap_option *current_opt = cm->options;
            struct mg_coap_option *prev_opt = 0;

            while (current_opt != NULL) {
                if (current_opt->number > new_option->number) {
                    break;
                }
                prev_opt = current_opt;
                current_opt = current_opt->next;
            }

            if (prev_opt != NULL) {
                prev_opt->next = new_option;
                new_option->next = current_opt;
            }
            else {
                /* insert new_option to the beginning */
                new_option->next = cm->options;
                cm->options = new_option;
            }
        }
    }

    return new_option;
}

/*
 * Fills CoAP header in mg_coap_message.
 *
 * Helper function.
 */
static char *coap_parse_header(char *ptr, struct mbuf *io,
    struct mg_coap_message *cm) {
    if (io->len < sizeof(uint32_t)) {
        cm->flags |= MG_COAP_NOT_ENOUGH_DATA;
        return NULL;
    }

    /*
     * Version (Ver):  2-bit unsigned integer.  Indicates the CoAP version
     * number.  Implementations of this specification MUST set this field
     * to 1 (01 binary).  Other values are reserved for future versions.
     * Messages with unknown version numbers MUST be silently ignored.
     */
    if (((uint8_t)*ptr >> 6) != 1) {
        cm->flags |= MG_COAP_IGNORE;
        return NULL;
    }

    /*
     * Type (T):  2-bit unsigned integer.  Indicates if this message is of
     * type Confirmable (0), Non-confirmable (1), Acknowledgement (2), or
     * Reset (3).
     */
    cm->msg_type = ((uint8_t)*ptr & 0x30) >> 4;
    cm->flags |= MG_COAP_MSG_TYPE_FIELD;

    /*
     * Token Length (TKL):  4-bit unsigned integer.  Indicates the length of
     * the variable-length Token field (0-8 bytes).  Lengths 9-15 are
     * reserved, MUST NOT be sent, and MUST be processed as a message
     * format error.
     */
    cm->token.len = *ptr & 0x0F;
    if (cm->token.len > 8) {
        cm->flags |= MG_COAP_FORMAT_ERROR;
        return NULL;
    }

    ptr++;

    /*
     * Code:  8-bit unsigned integer, split into a 3-bit class (most
     * significant bits) and a 5-bit detail (least significant bits)
     */
    cm->code_class = (uint8_t)*ptr >> 5;
    cm->code_detail = *ptr & 0x1F;
    cm->flags |= (MG_COAP_CODE_CLASS_FIELD | MG_COAP_CODE_DETAIL_FIELD);

    ptr++;

    /* Message ID:  16-bit unsigned integer in network byte order. */
    cm->msg_id = (uint8_t)*ptr << 8 | (uint8_t) * (ptr + 1);
    cm->flags |= MG_COAP_MSG_ID_FIELD;

    ptr += 2;

    return ptr;
}

/*
 * Fills token information in mg_coap_message.
 *
 * Helper function.
 */
static char *coap_get_token(char *ptr, struct mbuf *io,
    struct mg_coap_message *cm) {
    if (cm->token.len != 0) {
        if (ptr + cm->token.len > io->buf + io->len) {
            cm->flags |= MG_COAP_NOT_ENOUGH_DATA;
            return NULL;
        }
        else {
            cm->token.p = ptr;
            ptr += cm->token.len;
            cm->flags |= MG_COAP_TOKEN_FIELD;
        }
    }

    return ptr;
}

/*
 * Returns Option Delta or Length.
 *
 * Helper function.
 */
static int coap_get_ext_opt(char *ptr, struct mbuf *io, uint16_t *opt_info) {
    int ret = 0;

    if (*opt_info == 13) {
        /*
         * 13:  An 8-bit unsigned integer follows the initial byte and
         * indicates the Option Delta/Length minus 13.
         */
        if (ptr < io->buf + io->len) {
            *opt_info = (uint8_t)*ptr + 13;
            ret = sizeof(uint8_t);
        }
        else {
            ret = -1; /* LCOV_EXCL_LINE */
        }
    }
    else if (*opt_info == 14) {
        /*
         * 14:  A 16-bit unsigned integer in network byte order follows the
         * initial byte and indicates the Option Delta/Length minus 269.
         */
        if (ptr + sizeof(uint8_t) < io->buf + io->len) {
            *opt_info = ((uint8_t)*ptr << 8 | (uint8_t) * (ptr + 1)) + 269;
            ret = sizeof(uint16_t);
        }
        else {
            ret = -1; /* LCOV_EXCL_LINE */
        }
    }

    return ret;
}

/*
 * Fills options in mg_coap_message.
 *
 * Helper function.
 *
 * General options format:
 * +---------------+---------------+
 * | Option Delta  | Option Length |  1 byte
 * +---------------+---------------+
 * \    Option Delta (extended)    \  0-2 bytes
 * +-------------------------------+
 * / Option Length  (extended)     \  0-2 bytes
 * +-------------------------------+
 * \         Option Value          \  0 or more bytes
 * +-------------------------------+
 */
static char *coap_get_options(char *ptr, struct mbuf *io,
    struct mg_coap_message *cm) {
    uint16_t prev_opt = 0;

    if (ptr == io->buf + io->len) {
        /* end of packet, ok */
        return NULL;
    }

    /* 0xFF is payload marker */
    while (ptr < io->buf + io->len && (uint8_t)*ptr != 0xFF) {
        uint16_t option_delta, option_lenght;
        int optinfo_len;

        /* Option Delta:  4-bit unsigned integer */
        option_delta = ((uint8_t)*ptr & 0xF0) >> 4;
        /* Option Length:  4-bit unsigned integer */
        option_lenght = *ptr & 0x0F;

        if (option_delta == 15 || option_lenght == 15) {
            /*
             * 15:  Reserved for future use.  If the field is set to this value,
             * it MUST be processed as a message format error
             */
            cm->flags |= MG_COAP_FORMAT_ERROR;
            break;
        }

        ptr++;

        /* check for extended option delta */
        optinfo_len = coap_get_ext_opt(ptr, io, &option_delta);
        if (optinfo_len == -1) {
            cm->flags |= MG_COAP_NOT_ENOUGH_DATA; /* LCOV_EXCL_LINE */
            break;                                /* LCOV_EXCL_LINE */
        }

        ptr += optinfo_len;

        /* check or extended option lenght */
        optinfo_len = coap_get_ext_opt(ptr, io, &option_lenght);
        if (optinfo_len == -1) {
            cm->flags |= MG_COAP_NOT_ENOUGH_DATA; /* LCOV_EXCL_LINE */
            break;                                /* LCOV_EXCL_LINE */
        }

        ptr += optinfo_len;

        /*
         * Instead of specifying the Option Number directly, the instances MUST
         * appear in order of their Option Numbers and a delta encoding is used
         * between them.
         */
        option_delta += prev_opt;

        mg_coap_add_option(cm, option_delta, ptr, option_lenght);

        prev_opt = option_delta;

        if (ptr + option_lenght > io->buf + io->len) {
            cm->flags |= MG_COAP_NOT_ENOUGH_DATA; /* LCOV_EXCL_LINE */
            break;                                /* LCOV_EXCL_LINE */
        }

        ptr += option_lenght;
    }

    if ((cm->flags & MG_COAP_ERROR) != 0) {
        mg_coap_free_options(cm);
        return NULL;
    }

    cm->flags |= MG_COAP_OPTIOMG_FIELD;

    if (ptr == io->buf + io->len) {
        /* end of packet, ok */
        return NULL;
    }

    ptr++;

    return ptr;
}

uint32_t mg_coap_parse(struct mbuf *io, struct mg_coap_message *cm) {
    char *ptr;

    memset(cm, 0, sizeof(*cm));

    if ((ptr = coap_parse_header(io->buf, io, cm)) == NULL) {
        return cm->flags;
    }

    if ((ptr = coap_get_token(ptr, io, cm)) == NULL) {
        return cm->flags;
    }

    if ((ptr = coap_get_options(ptr, io, cm)) == NULL) {
        return cm->flags;
    }

    /* the rest is payload */
    cm->payload.len = io->len - (ptr - io->buf);
    if (cm->payload.len != 0) {
        cm->payload.p = ptr;
        cm->flags |= MG_COAP_PAYLOAD_FIELD;
    }

    return cm->flags;
}

/*
 * Calculates extended size of given Opt Number/Length in coap message.
 *
 * Helper function.
 */
static size_t coap_get_ext_opt_size(uint32_t value) {
    int ret = 0;

    if (value >= 13 && value <= 0xFF + 13) {
        ret = sizeof(uint8_t);
    }
    else if (value > 0xFF + 13 && value <= 0xFFFF + 269) {
        ret = sizeof(uint16_t);
    }

    return ret;
}

/*
 * Splits given Opt Number/Length into base and ext values.
 *
 * Helper function.
 */
static int coap_split_opt(uint32_t value, uint8_t *base, uint16_t *ext) {
    int ret = 0;

    if (value < 13) {
        *base = value;
    }
    else if (value >= 13 && value <= 0xFF + 13) {
        *base = 13;
        *ext = value - 13;
        ret = sizeof(uint8_t);
    }
    else if (value > 0xFF + 13 && value <= 0xFFFF + 269) {
        *base = 14;
        *ext = value - 269;
        ret = sizeof(uint16_t);
    }

    return ret;
}

/*
 * Puts uint16_t (in network order) into given char stream.
 *
 * Helper function.
 */
static char *coap_add_uint16(char *ptr, uint16_t val) {
    *ptr = val >> 8;
    ptr++;
    *ptr = val & 0x00FF;
    ptr++;
    return ptr;
}

/*
 * Puts extended value of Opt Number/Length into given char stream.
 *
 * Helper function.
 */
static char *coap_add_opt_info(char *ptr, uint16_t val, size_t len) {
    if (len == sizeof(uint8_t)) {
        *ptr = (char)val;
        ptr++;
    }
    else if (len == sizeof(uint16_t)) {
        ptr = coap_add_uint16(ptr, val);
    }

    return ptr;
}

/*
 * Verifies given mg_coap_message and calculates message size for it.
 *
 * Helper function.
 */
static uint32_t coap_calculate_packet_size(struct mg_coap_message *cm,
    size_t *len) {
    struct mg_coap_option *opt;
    uint32_t prev_opt_number;

    *len = 4; /* header */
    if (cm->msg_type > MG_COAP_MSG_MAX) {
        return MG_COAP_ERROR | MG_COAP_MSG_TYPE_FIELD;
    }
    if (cm->token.len > 8) {
        return MG_COAP_ERROR | MG_COAP_TOKEN_FIELD;
    }
    if (cm->code_class > 7) {
        return MG_COAP_ERROR | MG_COAP_CODE_CLASS_FIELD;
    }
    if (cm->code_detail > 31) {
        return MG_COAP_ERROR | MG_COAP_CODE_DETAIL_FIELD;
    }

    *len += cm->token.len;
    if (cm->payload.len != 0) {
        *len += cm->payload.len + 1; /* ... + 1; add payload marker */
    }

    opt = cm->options;
    prev_opt_number = 0;
    while (opt != NULL) {
        *len += 1; /* basic delta/length */
        *len += coap_get_ext_opt_size(opt->number - prev_opt_number);
        *len += coap_get_ext_opt_size((uint32_t)opt->value.len);
        /*
         * Current implementation performs check if
         * option_number > previous option_number and produces an error
         * TODO(alashkin): write design doc with limitations
         * May be resorting is more suitable solution.
         */
        if ((opt->next != NULL && opt->number > opt->next->number) ||
            opt->value.len > 0xFFFF + 269 ||
            opt->number - prev_opt_number > 0xFFFF + 269) {
            return MG_COAP_ERROR | MG_COAP_OPTIOMG_FIELD;
        }
        *len += opt->value.len;
        prev_opt_number = opt->number;
        opt = opt->next;
    }

    return 0;
}

uint32_t mg_coap_compose(struct mg_coap_message *cm, struct mbuf *io) {
    struct mg_coap_option *opt;
    uint32_t res, prev_opt_number;
    size_t prev_io_len, packet_size;
    char *ptr;

    res = coap_calculate_packet_size(cm, &packet_size);
    if (res != 0) {
        return res;
    }

    /* saving previous lenght to handle non-empty mbuf */
    prev_io_len = io->len;
    if (mbuf_append(io, NULL, packet_size) == 0) return MG_COAP_ERROR;
    ptr = io->buf + prev_io_len;

    /*
     * since cm is verified, it is possible to use bits shift operator
     * without additional zeroing of unused bits
     */

     /* ver: 2 bits, msg_type: 2 bits, toklen: 4 bits */
    *ptr = (1 << 6) | (cm->msg_type << 4) | (uint8_t)(cm->token.len);
    ptr++;

    /* code class: 3 bits, code detail: 5 bits */
    *ptr = (cm->code_class << 5) | (cm->code_detail);
    ptr++;

    ptr = coap_add_uint16(ptr, cm->msg_id);

    if (cm->token.len != 0) {
        memcpy(ptr, cm->token.p, cm->token.len);
        ptr += cm->token.len;
    }

    opt = cm->options;
    prev_opt_number = 0;
    while (opt != NULL) {
        uint8_t delta_base = 0, length_base = 0;
        uint16_t delta_ext = 0, length_ext = 0;

        size_t opt_delta_len =
            coap_split_opt(opt->number - prev_opt_number, &delta_base, &delta_ext);
        size_t opt_lenght_len =
            coap_split_opt((uint32_t)opt->value.len, &length_base, &length_ext);

        *ptr = (delta_base << 4) | length_base;
        ptr++;

        ptr = coap_add_opt_info(ptr, delta_ext, opt_delta_len);
        ptr = coap_add_opt_info(ptr, length_ext, opt_lenght_len);

        if (opt->value.len != 0) {
            memcpy(ptr, opt->value.p, opt->value.len);
            ptr += opt->value.len;
        }

        prev_opt_number = opt->number;
        opt = opt->next;
    }

    if (cm->payload.len != 0) {
        *ptr = (char)-1;
        ptr++;
        memcpy(ptr, cm->payload.p, cm->payload.len);
    }

    return 0;
}

uint32_t mg_coap_send_message(struct mg_connection *nc,
    struct mg_coap_message *cm) {
    struct mbuf packet_out;
    uint32_t compose_res;

    mbuf_init(&packet_out, 0);
    compose_res = mg_coap_compose(cm, &packet_out);
    if (compose_res != 0) {
        return compose_res; /* LCOV_EXCL_LINE */
    }

    mg_send(nc, packet_out.buf, (int)packet_out.len);
    mbuf_free(&packet_out);

    return 0;
}

uint32_t mg_coap_send_ack(struct mg_connection *nc, uint16_t msg_id) {
    struct mg_coap_message cm;
    memset(&cm, 0, sizeof(cm));
    cm.msg_type = MG_COAP_MSG_ACK;
    cm.msg_id = msg_id;

    return mg_coap_send_message(nc, &cm);
}

static void coap_handler(struct mg_connection *nc, int ev,
    void *ev_data MG_UD_ARG(void *user_data)) {
    struct mbuf *io = &nc->recv_mbuf;
    struct mg_coap_message cm;
    uint32_t parse_res;

    memset(&cm, 0, sizeof(cm));

    nc->handler(nc, ev, ev_data MG_UD_ARG(user_data));

    switch (ev) {
    case MG_EV_RECV:
        parse_res = mg_coap_parse(io, &cm);
        if ((parse_res & MG_COAP_IGNORE) == 0) {
            if ((cm.flags & MG_COAP_NOT_ENOUGH_DATA) != 0) {
                /*
                 * Since we support UDP only
                 * MG_COAP_NOT_ENOUGH_DATA == MG_COAP_FORMAT_ERROR
                 */
                cm.flags |= MG_COAP_FORMAT_ERROR; /* LCOV_EXCL_LINE */
            }                                   /* LCOV_EXCL_LINE */
            nc->handler(nc, MG_COAP_EVENT_BASE + cm.msg_type,
                &cm MG_UD_ARG(user_data));
        }

        mg_coap_free_options(&cm);
        mbuf_remove(io, io->len);
        break;
    }
}
/*
 * Attach built-in CoAP event handler to the given connection.
 *
 * The user-defined event handler will receive following extra events:
 *
 * - MG_EV_COAP_CON
 * - MG_EV_COAP_NOC
 * - MG_EV_COAP_ACK
 * - MG_EV_COAP_RST
 */
int mg_set_protocol_coap(struct mg_connection *nc) {
    /* supports UDP only */
    if ((nc->flags & MG_F_UDP) == 0) {
        return -1;
    }

    nc->proto_handler = coap_handler;

    return 0;
}

#endif /* MG_ENABLE_COAP */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_sntp.c"
#endif
/*
 * Copyright (c) 2016 Cesanta Software Limited
 * All rights reserved
 */

 /* Amalgamated: #include "mg_internal.h" */
 /* Amalgamated: #include "mg_sntp.h" */
 /* Amalgamated: #include "mg_util.h" */

#if MG_ENABLE_SNTP

#define SNTP_TIME_OFFSET 2208988800

#ifndef SNTP_TIMEOUT
#define SNTP_TIMEOUT 10
#endif

#ifndef SNTP_ATTEMPTS
#define SNTP_ATTEMPTS 3
#endif

static uint64_t mg_get_sec(uint64_t val) {
    return (val & 0xFFFFFFFF00000000) >> 32;
}

static uint64_t mg_get_usec(uint64_t val) {
    uint64_t tmp = (val & 0x00000000FFFFFFFF);
    tmp *= 1000000;
    tmp >>= 32;
    return tmp;
}

static void mg_ntp_to_tv(uint64_t val, struct timeval *tv) {
    uint64_t tmp;
    tmp = mg_get_sec(val);
    tmp -= SNTP_TIME_OFFSET;
    tv->tv_sec = tmp;
    tv->tv_usec = mg_get_usec(val);
}

static void mg_get_ntp_ts(const char *ntp, uint64_t *val) {
    uint32_t tmp;
    memcpy(&tmp, ntp, sizeof(tmp));
    tmp = ntohl(tmp);
    *val = (uint64_t)tmp << 32;
    memcpy(&tmp, ntp + 4, sizeof(tmp));
    tmp = ntohl(tmp);
    *val |= tmp;
}

void mg_sntp_send_request(struct mg_connection *c) {
    uint8_t buf[48] = { 0 };
    /*
     * header - 8 bit:
     * LI (2 bit) - 3 (not in sync), VN (3 bit) - 4 (version),
     * mode (3 bit) - 3 (client)
     */
    buf[0] = (3 << 6) | (4 << 3) | 3;

    /*
     * Next fields should be empty in client request
     * stratum, 8 bit
     * poll interval, 8 bit
     * rrecision, 8 bit
     * root delay, 32 bit
     * root dispersion, 32 bit
     * ref id, 32 bit
     * ref timestamp, 64 bit
     * originate Timestamp, 64 bit
     * receive Timestamp, 64 bit
    */

    /*
     * convert time to sntp format (sntp starts from 00:00:00 01.01.1900)
     * according to rfc868 it is 2208988800L sec
     * this information is used to correct roundtrip delay
     * but if local clock is absolutely broken (and doesn't work even
     * as simple timer), it is better to disable it
    */
#ifndef MG_SNTP_NO_DELAY_CORRECTION
    uint32_t sec;
    sec = htonl((uint32_t)(mg_time() + SNTP_TIME_OFFSET));
    memcpy(&buf[40], &sec, sizeof(sec));
#endif

    mg_send(c, buf, sizeof(buf));
}

#ifndef MG_SNTP_NO_DELAY_CORRECTION
static uint64_t mg_calculate_delay(uint64_t t1, uint64_t t2, uint64_t t3) {
    /* roundloop delay = (T4 - T1) - (T3 - T2) */
    uint64_t d1 = ((mg_time() + SNTP_TIME_OFFSET) * 1000000) -
        (mg_get_sec(t1) * 1000000 + mg_get_usec(t1));
    uint64_t d2 = (mg_get_sec(t3) * 1000000 + mg_get_usec(t3)) -
        (mg_get_sec(t2) * 1000000 + mg_get_usec(t2));

    return (d1 > d2) ? d1 - d2 : 0;
}
#endif

MG_INTERNAL int mg_sntp_parse_reply(const char *buf, int len,
    struct mg_sntp_message *msg) {
    uint8_t hdr;
    uint64_t trsm_ts_T3, delay = 0;
    int mode;
    struct timeval tv;

    if (len < 48) {
        return -1;
    }

    hdr = buf[0];

    if ((hdr & 0x38) >> 3 != 4) {
        /* Wrong version */
        return -1;
    }

    mode = hdr & 0x7;
    if (mode != 4 && mode != 5) {
        /* Not a server reply */
        return -1;
    }

    memset(msg, 0, sizeof(*msg));

    msg->kiss_of_death = (buf[1] == 0); /* Server asks to not send requests */

    mg_get_ntp_ts(&buf[40], &trsm_ts_T3);

#ifndef MG_SNTP_NO_DELAY_CORRECTION
    {
        uint64_t orig_ts_T1, recv_ts_T2;
        mg_get_ntp_ts(&buf[24], &orig_ts_T1);
        mg_get_ntp_ts(&buf[32], &recv_ts_T2);
        delay = mg_calculate_delay(orig_ts_T1, recv_ts_T2, trsm_ts_T3);
    }
#endif

    mg_ntp_to_tv(trsm_ts_T3, &tv);

    msg->time = (double)tv.tv_sec + (((double)tv.tv_usec + delay) / 1000000.0);

    return 0;
}

static void mg_sntp_handler(struct mg_connection *c, int ev,
    void *ev_data MG_UD_ARG(void *user_data)) {
    struct mbuf *io = &c->recv_mbuf;
    struct mg_sntp_message msg;

    c->handler(c, ev, ev_data MG_UD_ARG(user_data));

    switch (ev) {
    case MG_EV_RECV: {
        if (mg_sntp_parse_reply(io->buf, io->len, &msg) < 0) {
            DBG(("Invalid SNTP packet received (%d)", (int)io->len));
            c->handler(c, MG_SNTP_MALFORMED_REPLY, NULL MG_UD_ARG(user_data));
        }
        else {
            c->handler(c, MG_SNTP_REPLY, (void *)&msg MG_UD_ARG(user_data));
        }

        mbuf_remove(io, io->len);
        break;
    }
    }
}

int mg_set_protocol_sntp(struct mg_connection *c) {
    if ((c->flags & MG_F_UDP) == 0) {
        return -1;
    }

    c->proto_handler = mg_sntp_handler;

    return 0;
}

struct mg_connection *mg_sntp_connect(struct mg_mgr *mgr,
    MG_CB(mg_event_handler_t event_handler,
        void *user_data),
    const char *sntp_server_name) {
    struct mg_connection *c = NULL;
    char url[100], *p_url = url;
    const char *proto = "", *port = "", *tmp;

    /* If port is not specified, use default (123) */
    tmp = strchr(sntp_server_name, ':');
    if (tmp != NULL && *(tmp + 1) == '/') {
        tmp = strchr(tmp + 1, ':');
    }

    if (tmp == NULL) {
        port = ":123";
    }

    /* Add udp:// if needed */
    if (strncmp(sntp_server_name, "udp://", 6) != 0) {
        proto = "udp://";
    }

    mg_asprintf(&p_url, sizeof(url), "%s%s%s", proto, sntp_server_name, port);

    c = mg_connect(mgr, p_url, event_handler MG_UD_ARG(user_data));

    if (c == NULL) {
        goto cleanup;
    }

    mg_set_protocol_sntp(c);

cleanup:
    if (p_url != url) {
        MG_FREE(p_url);
    }

    return c;
}

struct sntp_data {
    mg_event_handler_t hander;
    int count;
};

static void mg_sntp_util_ev_handler(struct mg_connection *c, int ev,
    void *ev_data MG_UD_ARG(void *user_data)) {
#if !MG_ENABLE_CALLBACK_USERDATA
    void *user_data = c->user_data;
#endif
    struct sntp_data *sd = (struct sntp_data *) user_data;

    switch (ev) {
    case MG_EV_CONNECT:
        if (*(int *)ev_data != 0) {
            mg_call(c, sd->hander, c->user_data, MG_SNTP_FAILED, NULL);
            break;
        }
        /* fallthrough */
    case MG_EV_TIMER:
        if (sd->count <= SNTP_ATTEMPTS) {
            mg_sntp_send_request(c);
            mg_set_timer(c, mg_time() + 10);
            sd->count++;
        }
        else {
            mg_call(c, sd->hander, c->user_data, MG_SNTP_FAILED, NULL);
            c->flags |= MG_F_CLOSE_IMMEDIATELY;
        }
        break;
    case MG_SNTP_MALFORMED_REPLY:
        mg_call(c, sd->hander, c->user_data, MG_SNTP_FAILED, NULL);
        c->flags |= MG_F_CLOSE_IMMEDIATELY;
        break;
    case MG_SNTP_REPLY:
        mg_call(c, sd->hander, c->user_data, MG_SNTP_REPLY, ev_data);
        c->flags |= MG_F_CLOSE_IMMEDIATELY;
        break;
    case MG_EV_CLOSE:
        MG_FREE(user_data);
        c->user_data = NULL;
        break;
    }
}

struct mg_connection *mg_sntp_get_time(struct mg_mgr *mgr,
    mg_event_handler_t event_handler,
    const char *sntp_server_name) {
    struct mg_connection *c;
    struct sntp_data *sd = (struct sntp_data *) MG_CALLOC(1, sizeof(*sd));
    if (sd == NULL) {
        return NULL;
    }

    c = mg_sntp_connect(mgr, MG_CB(mg_sntp_util_ev_handler, sd),
        sntp_server_name);
    if (c == NULL) {
        MG_FREE(sd);
        return NULL;
    }

    sd->hander = event_handler;
#if !MG_ENABLE_CALLBACK_USERDATA
    c->user_data = sd;
#endif

    return c;
}

#endif /* MG_ENABLE_SNTP */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_socks.c"
#endif
/*
 * Copyright (c) 2017 Cesanta Software Limited
 * All rights reserved
 */

#if MG_ENABLE_SOCKS

 /* Amalgamated: #include "mg_socks.h" */
 /* Amalgamated: #include "mg_internal.h" */

 /*
  *  https://www.ietf.org/rfc/rfc1928.txt paragraph 3, handle client handshake
  *
  *  +----+----------+----------+
  *  |VER | NMETHODS | METHODS  |
  *  +----+----------+----------+
  *  | 1  |    1     | 1 to 255 |
  *  +----+----------+----------+
  */
static void mg_socks5_handshake(struct mg_connection *c) {
    struct mbuf *r = &c->recv_mbuf;
    if (r->buf[0] != MG_SOCKS_VERSION) {
        c->flags |= MG_F_CLOSE_IMMEDIATELY;
    }
    else if (r->len > 2 && (size_t)r->buf[1] + 2 <= r->len) {
        /* https://www.ietf.org/rfc/rfc1928.txt paragraph 3 */
        unsigned char reply[2] = { MG_SOCKS_VERSION, MG_SOCKS_HANDSHAKE_FAILURE };
        int i;
        for (i = 2; i < r->buf[1] + 2; i++) {
            /* TODO(lsm): support other auth methods */
            if (r->buf[i] == MG_SOCKS_HANDSHAKE_NOAUTH) reply[1] = r->buf[i];
        }
        mbuf_remove(r, 2 + r->buf[1]);
        mg_send(c, reply, sizeof(reply));
        c->flags |= MG_SOCKS_HANDSHAKE_DONE; /* Mark handshake done */
    }
}

static void disband(struct mg_connection *c) {
    struct mg_connection *c2 = (struct mg_connection *) c->user_data;
    if (c2 != NULL) {
        c2->flags |= MG_F_SEND_AND_CLOSE;
        c2->user_data = NULL;
    }
    c->flags |= MG_F_SEND_AND_CLOSE;
    c->user_data = NULL;
}

static void relay_data(struct mg_connection *c) {
    struct mg_connection *c2 = (struct mg_connection *) c->user_data;
    if (c2 != NULL) {
        mg_send(c2, c->recv_mbuf.buf, c->recv_mbuf.len);
        mbuf_remove(&c->recv_mbuf, c->recv_mbuf.len);
    }
    else {
        c->flags |= MG_F_SEND_AND_CLOSE;
    }
}

static void serv_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
    if (ev == MG_EV_CLOSE) {
        disband(c);
    }
    else if (ev == MG_EV_RECV) {
        relay_data(c);
    }
    else if (ev == MG_EV_CONNECT) {
        int res = *(int *)ev_data;
        if (res != 0) LOG(LL_ERROR, ("connect error: %d", res));
    }
}

static void mg_socks5_connect(struct mg_connection *c, const char *addr) {
    struct mg_connection *serv = mg_connect(c->mgr, addr, serv_ev_handler);
    serv->user_data = c;
    c->user_data = serv;
}

/*
 *  Request, https://www.ietf.org/rfc/rfc1928.txt paragraph 4
 *
 *  +----+-----+-------+------+----------+----------+
 *  |VER | CMD |  RSV  | ATYP | DST.ADDR | DST.PORT |
 *  +----+-----+-------+------+----------+----------+
 *  | 1  |  1  | X'00' |  1   | Variable |    2     |
 *  +----+-----+-------+------+----------+----------+
 */
static void mg_socks5_handle_request(struct mg_connection *c) {
    struct mbuf *r = &c->recv_mbuf;
    unsigned char *p = (unsigned char *)r->buf;
    unsigned char addr_len = 4, reply = MG_SOCKS_SUCCESS;
    int ver, cmd, atyp;
    char addr[300];

    if (r->len < 8) return; /* return if not fully buffered. min DST.ADDR is 2 */
    ver = p[0];
    cmd = p[1];
    atyp = p[3];

    /* TODO(lsm): support other commands */
    if (ver != MG_SOCKS_VERSION || cmd != MG_SOCKS_CMD_CONNECT) {
        reply = MG_SOCKS_CMD_NOT_SUPPORTED;
    }
    else if (atyp == MG_SOCKS_ADDR_IPV4) {
        addr_len = 4;
        if (r->len < (size_t)addr_len + 6) return; /* return if not buffered */
        snprintf(addr, sizeof(addr), "%d.%d.%d.%d:%d", p[4], p[5], p[6], p[7],
            p[8] << 8 | p[9]);
        mg_socks5_connect(c, addr);
    }
    else if (atyp == MG_SOCKS_ADDR_IPV6) {
        addr_len = 16;
        if (r->len < (size_t)addr_len + 6) return; /* return if not buffered */
        snprintf(addr, sizeof(addr), "[%x:%x:%x:%x:%x:%x:%x:%x]:%d",
            p[4] << 8 | p[5], p[6] << 8 | p[7], p[8] << 8 | p[9],
            p[10] << 8 | p[11], p[12] << 8 | p[13], p[14] << 8 | p[15],
            p[16] << 8 | p[17], p[18] << 8 | p[19], p[20] << 8 | p[21]);
        mg_socks5_connect(c, addr);
    }
    else if (atyp == MG_SOCKS_ADDR_DOMAIN) {
        addr_len = p[4] + 1;
        if (r->len < (size_t)addr_len + 6) return; /* return if not buffered */
        snprintf(addr, sizeof(addr), "%.*s:%d", p[4], p + 5,
            p[4 + addr_len] << 8 | p[4 + addr_len + 1]);
        mg_socks5_connect(c, addr);
    }
    else {
        reply = MG_SOCKS_ADDR_NOT_SUPPORTED;
    }

    /*
     *  Reply, https://www.ietf.org/rfc/rfc1928.txt paragraph 5
     *
     *  +----+-----+-------+------+----------+----------+
     *  |VER | REP |  RSV  | ATYP | BND.ADDR | BND.PORT |
     *  +----+-----+-------+------+----------+----------+
     *  | 1  |  1  | X'00' |  1   | Variable |    2     |
     *  +----+-----+-------+------+----------+----------+
     */
    {
        unsigned char buf[] = { MG_SOCKS_VERSION, reply, 0 };
        mg_send(c, buf, sizeof(buf));
    }
    mg_send(c, r->buf + 3, addr_len + 1 + 2);

    mbuf_remove(r, 6 + addr_len);      /* Remove request from the input stream */
    c->flags |= MG_SOCKS_CONNECT_DONE; /* Mark ourselves as connected */
}

static void socks_handler(struct mg_connection *c, int ev, void *ev_data) {
    if (ev == MG_EV_RECV) {
        if (!(c->flags & MG_SOCKS_HANDSHAKE_DONE)) mg_socks5_handshake(c);
        if (c->flags & MG_SOCKS_HANDSHAKE_DONE &&
            !(c->flags & MG_SOCKS_CONNECT_DONE)) {
            mg_socks5_handle_request(c);
        }
        if (c->flags & MG_SOCKS_CONNECT_DONE) relay_data(c);
    }
    else if (ev == MG_EV_CLOSE) {
        disband(c);
    }
    (void)ev_data;
}

void mg_set_protocol_socks(struct mg_connection *c) {
    c->proto_handler = socks_handler;
}
#endif
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/cc3200/cc3200_libc.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#if CS_PLATFORM == CS_P_CC3200

 /* Amalgamated: #include "common/mg_mem.h" */
#include <stdio.h>
#include <string.h>

#ifndef __TI_COMPILER_VERSION__
#include <reent.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <unistd.h>
#endif

#include <inc/hw_types.h>
#include <inc/hw_memmap.h>
#include <driverlib/prcm.h>
#include <driverlib/rom.h>
#include <driverlib/rom_map.h>
#include <driverlib/uart.h>
#include <driverlib/utils.h>

#define CONSOLE_UART UARTA0_BASE

#ifdef __TI_COMPILER_VERSION__
int asprintf(char **strp, const char *fmt, ...) {
    va_list ap;
    int len;

    *strp = MG_MALLOC(BUFSIZ);
    if (*strp == NULL) return -1;

    va_start(ap, fmt);
    len = vsnprintf(*strp, BUFSIZ, fmt, ap);
    va_end(ap);

    if (len > 0) {
        *strp = MG_REALLOC(*strp, len + 1);
        if (*strp == NULL) return -1;
    }

    if (len >= BUFSIZ) {
        va_start(ap, fmt);
        len = vsnprintf(*strp, len + 1, fmt, ap);
        va_end(ap);
    }

    return len;
}

#if MG_TI_NO_HOST_INTERFACE
time_t HOSTtime() {
    struct timeval tp;
    gettimeofday(&tp, NULL);
    return tp.tv_sec;
}
#endif

#endif /* __TI_COMPILER_VERSION__ */

void fprint_str(FILE *fp, const char *str) {
    while (*str != '\0') {
        if (*str == '\n') MAP_UARTCharPut(CONSOLE_UART, '\r');
        MAP_UARTCharPut(CONSOLE_UART, *str++);
    }
}

void _exit(int status) {
    fprint_str(stderr, "_exit\n");
    /* cause an unaligned access exception, that will drop you into gdb */
    *(int *)1 = status;
    while (1)
        ; /* avoid gcc warning because stdlib abort() has noreturn attribute */
}

void _not_implemented(const char *what) {
    fprint_str(stderr, what);
    fprint_str(stderr, " is not implemented\n");
    _exit(42);
}

int _kill(int pid, int sig) {
    (void)pid;
    (void)sig;
    _not_implemented("_kill");
    return -1;
}

int _getpid() {
    fprint_str(stderr, "_getpid is not implemented\n");
    return 42;
}

int _isatty(int fd) {
    /* 0, 1 and 2 are TTYs. */
    return fd < 2;
}

#endif /* CS_PLATFORM == CS_P_CC3200 */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/msp432/msp432_libc.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#if CS_PLATFORM == CS_P_MSP432

#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Clock.h>

int gettimeofday(struct timeval *tp, void *tzp) {
    uint32_t ticks = Clock_getTicks();
    tp->tv_sec = ticks / 1000;
    tp->tv_usec = (ticks % 1000) * 1000;
    return 0;
}

#endif /* CS_PLATFORM == CS_P_MSP432 */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/nrf5/nrf5_libc.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#if (CS_PLATFORM == CS_P_NRF51 || CS_PLATFORM == CS_P_NRF52) && \
    defined(__ARMCC_VERSION)
int gettimeofday(struct timeval *tp, void *tzp) {
    /* TODO */
    tp->tv_sec = 0;
    tp->tv_usec = 0;
    return 0;
}
#endif
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/simplelink/sl_fs_slfs.h"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CS_COMMON_PLATFORMS_SIMPLELINK_SL_FS_SLFS_H_
#define CS_COMMON_PLATFORMS_SIMPLELINK_SL_FS_SLFS_H_

#if defined(MG_FS_SLFS)

#include <stdio.h>
#ifndef __TI_COMPILER_VERSION__
#include <unistd.h>
#include <sys/stat.h>
#endif

#define MAX_OPEN_SLFS_FILES 8

 /* Indirect libc interface - same functions, different names. */
int fs_slfs_open(const char *pathname, int flags, mode_t mode);
int fs_slfs_close(int fd);
ssize_t fs_slfs_read(int fd, void *buf, size_t count);
ssize_t fs_slfs_write(int fd, const void *buf, size_t count);
int fs_slfs_stat(const char *pathname, struct stat *s);
int fs_slfs_fstat(int fd, struct stat *s);
off_t fs_slfs_lseek(int fd, off_t offset, int whence);
int fs_slfs_unlink(const char *filename);
int fs_slfs_rename(const char *from, const char *to);

void fs_slfs_set_file_size(const char *name, size_t size);
void fs_slfs_set_file_flags(const char *name, uint32_t flags, uint32_t *token);
void fs_slfs_unset_file_flags(const char *name);

#endif /* defined(MG_FS_SLFS) */

#endif /* CS_COMMON_PLATFORMS_SIMPLELINK_SL_FS_SLFS_H_ */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/simplelink/sl_fs_slfs.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

 /* Standard libc interface to TI SimpleLink FS. */

#if defined(MG_FS_SLFS) || defined(CC3200_FS_SLFS)

/* Amalgamated: #include "common/platforms/simplelink/sl_fs_slfs.h" */

#include <errno.h>

#if CS_PLATFORM == CS_P_CC3200
#include <inc/hw_types.h>
#endif

/* Amalgamated: #include "common/cs_dbg.h" */
/* Amalgamated: #include "common/mg_mem.h" */

#if SL_MAJOR_VERSION_NUM < 2
int slfs_open(const unsigned char *fname, uint32_t flags, uint32_t *token) {
    _i32 fh;
    _i32 r = sl_FsOpen(fname, flags, (unsigned long *)token, &fh);
    return (r < 0 ? r : fh);
}
#else /* SL_MAJOR_VERSION_NUM >= 2 */
int slfs_open(const unsigned char *fname, uint32_t flags, uint32_t *token) {
    return sl_FsOpen(fname, flags, (unsigned long *)token);
}
#endif

/* From sl_fs.c */
int set_errno(int e);
const char *drop_dir(const char *fname, bool *is_slfs);

/*
 * With SLFS, you have to pre-declare max file size. Yes. Really.
 * 64K should be enough for everyone. Right?
 */
#ifndef FS_SLFS_MAX_FILE_SIZE
#define FS_SLFS_MAX_FILE_SIZE (64 * 1024)
#endif

struct sl_file_open_info {
    char *name;
    size_t size;
    uint32_t flags;
    uint32_t *token;
};

struct sl_fd_info {
    _i32 fh;
    _off_t pos;
    size_t size;
};

static struct sl_fd_info s_sl_fds[MAX_OPEN_SLFS_FILES];
static struct sl_file_open_info s_sl_file_open_infos[MAX_OPEN_SLFS_FILES];

static struct sl_file_open_info *fs_slfs_find_foi(const char *name,
    bool create);

static int sl_fs_to_errno(_i32 r) {
    DBG(("SL error: %d", (int)r));
    switch (r) {
    case SL_FS_OK:
        return 0;
    case SL_ERROR_FS_FILE_NAME_EXIST:
        return EEXIST;
    case SL_ERROR_FS_WRONG_FILE_NAME:
        return EINVAL;
    case SL_ERROR_FS_NO_AVAILABLE_NV_INDEX:
    case SL_ERROR_FS_NOT_ENOUGH_STORAGE_SPACE:
        return ENOSPC;
    case SL_ERROR_FS_FAILED_TO_ALLOCATE_MEM:
        return ENOMEM;
    case SL_ERROR_FS_FILE_NOT_EXISTS:
        return ENOENT;
    case SL_ERROR_FS_NOT_SUPPORTED:
        return ENOTSUP;
    }
    return ENXIO;
}

int fs_slfs_open(const char *pathname, int flags, mode_t mode) {
    int fd;
    for (fd = 0; fd < MAX_OPEN_SLFS_FILES; fd++) {
        if (s_sl_fds[fd].fh <= 0) break;
    }
    if (fd >= MAX_OPEN_SLFS_FILES) return set_errno(ENOMEM);
    struct sl_fd_info *fi = &s_sl_fds[fd];

    /*
     * Apply path manipulations again, in case we got here directly
     * (via TI libc's "add_device").
     */
    pathname = drop_dir(pathname, NULL);

    _u32 am = 0;
    fi->size = (size_t)-1;
    int rw = (flags & 3);
    size_t new_size = 0;
    struct sl_file_open_info *foi =
        fs_slfs_find_foi(pathname, false /* create */);
    if (foi != NULL) {
        LOG(LL_DEBUG, ("FOI for %s: %d 0x%x %p", pathname, (int)foi->size,
            (unsigned int)foi->flags, foi->token));
    }
    if (rw == O_RDONLY) {
        SlFsFileInfo_t sl_fi;
        _i32 r = sl_FsGetInfo((const _u8 *)pathname, 0, &sl_fi);
        if (r == SL_FS_OK) {
            fi->size = SL_FI_FILE_SIZE(sl_fi);
        }
        am = SL_FS_READ;
    }
    else {
        if (!(flags & O_TRUNC) || (flags & O_APPEND)) {
            // FailFS files cannot be opened for append and will be truncated
            // when opened for write.
            return set_errno(ENOTSUP);
        }
        if (flags & O_CREAT) {
            if (foi->size > 0) {
                new_size = foi->size;
            }
            else {
                new_size = FS_SLFS_MAX_FILE_SIZE;
            }
            am = FS_MODE_OPEN_CREATE(new_size, 0);
        }
        else {
            am = SL_FS_WRITE;
        }
#if SL_MAJOR_VERSION_NUM >= 2
        am |= SL_FS_OVERWRITE;
#endif
    }
    uint32_t *token = NULL;
    if (foi != NULL) {
        am |= foi->flags;
        token = foi->token;
    }
    fi->fh = slfs_open((_u8 *)pathname, am, token);
    LOG(LL_DEBUG, ("sl_FsOpen(%s, 0x%x, %p) sz %u = %d", pathname, (int)am,
        token, (unsigned int)new_size, (int)fi->fh));
    int r;
    if (fi->fh >= 0) {
        fi->pos = 0;
        r = fd;
    }
    else {
        r = set_errno(sl_fs_to_errno(fi->fh));
    }
    return r;
}

int fs_slfs_close(int fd) {
    struct sl_fd_info *fi = &s_sl_fds[fd];
    if (fi->fh <= 0) return set_errno(EBADF);
    _i32 r = sl_FsClose(fi->fh, NULL, NULL, 0);
    LOG(LL_DEBUG, ("sl_FsClose(%d) = %d", (int)fi->fh, (int)r));
    s_sl_fds[fd].fh = -1;
    return set_errno(sl_fs_to_errno(r));
}

ssize_t fs_slfs_read(int fd, void *buf, size_t count) {
    struct sl_fd_info *fi = &s_sl_fds[fd];
    if (fi->fh <= 0) return set_errno(EBADF);
    /* Simulate EOF. sl_FsRead @ file_size return SL_FS_ERR_OFFSET_OUT_OF_RANGE.
     */
    if (fi->pos == fi->size) return 0;
    _i32 r = sl_FsRead(fi->fh, fi->pos, buf, count);
    DBG(("sl_FsRead(%d, %d, %d) = %d", (int)fi->fh, (int)fi->pos, (int)count,
        (int)r));
    if (r >= 0) {
        fi->pos += r;
        return r;
    }
    return set_errno(sl_fs_to_errno(r));
}

ssize_t fs_slfs_write(int fd, const void *buf, size_t count) {
    struct sl_fd_info *fi = &s_sl_fds[fd];
    if (fi->fh <= 0) return set_errno(EBADF);
    _i32 r = sl_FsWrite(fi->fh, fi->pos, (_u8 *)buf, count);
    DBG(("sl_FsWrite(%d, %d, %d) = %d", (int)fi->fh, (int)fi->pos, (int)count,
        (int)r));
    if (r >= 0) {
        fi->pos += r;
        return r;
    }
    return set_errno(sl_fs_to_errno(r));
}

int fs_slfs_stat(const char *pathname, struct stat *s) {
    SlFsFileInfo_t sl_fi;
    /*
     * Apply path manipulations again, in case we got here directly
     * (via TI libc's "add_device").
     */
    pathname = drop_dir(pathname, NULL);
    _i32 r = sl_FsGetInfo((const _u8 *)pathname, 0, &sl_fi);
    if (r == SL_FS_OK) {
        s->st_mode = S_IFREG | 0666;
        s->st_nlink = 1;
        s->st_size = SL_FI_FILE_SIZE(sl_fi);
        return 0;
    }
    return set_errno(sl_fs_to_errno(r));
}

int fs_slfs_fstat(int fd, struct stat *s) {
    struct sl_fd_info *fi = &s_sl_fds[fd];
    if (fi->fh <= 0) return set_errno(EBADF);
    s->st_mode = 0666;
    s->st_mode = S_IFREG | 0666;
    s->st_nlink = 1;
    s->st_size = fi->size;
    return 0;
}

off_t fs_slfs_lseek(int fd, off_t offset, int whence) {
    if (s_sl_fds[fd].fh <= 0) return set_errno(EBADF);
    switch (whence) {
    case SEEK_SET:
        s_sl_fds[fd].pos = offset;
        break;
    case SEEK_CUR:
        s_sl_fds[fd].pos += offset;
        break;
    case SEEK_END:
        return set_errno(ENOTSUP);
    }
    return 0;
}

int fs_slfs_unlink(const char *pathname) {
    /*
     * Apply path manipulations again, in case we got here directly
     * (via TI libc's "add_device").
     */
    pathname = drop_dir(pathname, NULL);
    return set_errno(sl_fs_to_errno(sl_FsDel((const _u8 *)pathname, 0)));
}

int fs_slfs_rename(const char *from, const char *to) {
    return set_errno(ENOTSUP);
}

static struct sl_file_open_info *fs_slfs_find_foi(const char *name,
    bool create) {
    int i = 0;
    for (i = 0; i < MAX_OPEN_SLFS_FILES; i++) {
        if (s_sl_file_open_infos[i].name != NULL &&
            strcmp(drop_dir(s_sl_file_open_infos[i].name, NULL), name) == 0) {
            break;
        }
    }
    if (i != MAX_OPEN_SLFS_FILES) return &s_sl_file_open_infos[i];
    if (!create) return NULL;
    for (i = 0; i < MAX_OPEN_SLFS_FILES; i++) {
        if (s_sl_file_open_infos[i].name == NULL) break;
    }
    if (i == MAX_OPEN_SLFS_FILES) {
        i = 0; /* Evict a random slot. */
    }
    if (s_sl_file_open_infos[i].name != NULL) {
        free(s_sl_file_open_infos[i].name);
    }
    s_sl_file_open_infos[i].name = strdup(name);
    return &s_sl_file_open_infos[i];
}

void fs_slfs_set_file_size(const char *name, size_t size) {
    struct sl_file_open_info *foi = fs_slfs_find_foi(name, true /* create */);
    foi->size = size;
}

void fs_slfs_set_file_flags(const char *name, uint32_t flags, uint32_t *token) {
    struct sl_file_open_info *foi = fs_slfs_find_foi(name, true /* create */);
    foi->flags = flags;
    foi->token = token;
}

void fs_slfs_unset_file_flags(const char *name) {
    struct sl_file_open_info *foi = fs_slfs_find_foi(name, false /* create */);
    if (foi == NULL) return;
    free(foi->name);
    memset(foi, 0, sizeof(*foi));
}

#endif /* defined(MG_FS_SLFS) || defined(CC3200_FS_SLFS) */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/simplelink/sl_fs.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#if MG_NET_IF == MG_NET_IF_SIMPLELINK && \
    (defined(MG_FS_SLFS) || defined(MG_FS_SPIFFS))

int set_errno(int e) {
    errno = e;
    return (e == 0 ? 0 : -1);
}

const char *drop_dir(const char *fname, bool *is_slfs) {
    if (is_slfs != NULL) {
        *is_slfs = (strncmp(fname, "SL:", 3) == 0);
        if (*is_slfs) fname += 3;
    }
    /* Drop "./", if any */
    if (fname[0] == '.' && fname[1] == '/') {
        fname += 2;
    }
    /*
     * Drop / if it is the only one in the path.
     * This allows use of /pretend/directories but serves /file.txt as normal.
     */
    if (fname[0] == '/' && strchr(fname + 1, '/') == NULL) {
        fname++;
    }
    return fname;
}

#if !defined(MG_FS_NO_VFS)

#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef __TI_COMPILER_VERSION__
#include <file.h>
#endif

/* Amalgamated: #include "common/cs_dbg.h" */
/* Amalgamated: #include "common/platform.h" */

#ifdef CC3200_FS_SPIFFS
/* Amalgamated: #include "cc3200_fs_spiffs.h" */
#endif

#ifdef MG_FS_SLFS
/* Amalgamated: #include "sl_fs_slfs.h" */
#endif

#define NUM_SYS_FDS 3
#define SPIFFS_FD_BASE 10
#define SLFS_FD_BASE 100

#if !defined(MG_UART_CHAR_PUT) && !defined(MG_UART_WRITE)
#if CS_PLATFORM == CS_P_CC3200
#include <inc/hw_types.h>
#include <inc/hw_memmap.h>
#include <driverlib/rom.h>
#include <driverlib/rom_map.h>
#include <driverlib/uart.h>
#define MG_UART_CHAR_PUT(fd, c) MAP_UARTCharPut(UARTA0_BASE, c);
#else
#define MG_UART_WRITE(fd, buf, len)
#endif /* CS_PLATFORM == CS_P_CC3200 */
#endif /* !MG_UART_CHAR_PUT */

enum fd_type {
    FD_INVALID,
    FD_SYS,
#ifdef CC3200_FS_SPIFFS
    FD_SPIFFS,
#endif
#ifdef MG_FS_SLFS
    FD_SLFS
#endif
};
static int fd_type(int fd) {
    if (fd >= 0 && fd < NUM_SYS_FDS) return FD_SYS;
#ifdef CC3200_FS_SPIFFS
    if (fd >= SPIFFS_FD_BASE && fd < SPIFFS_FD_BASE + MAX_OPEN_SPIFFS_FILES) {
        return FD_SPIFFS;
    }
#endif
#ifdef MG_FS_SLFS
    if (fd >= SLFS_FD_BASE && fd < SLFS_FD_BASE + MAX_OPEN_SLFS_FILES) {
        return FD_SLFS;
    }
#endif
    return FD_INVALID;
}

#if MG_TI_NO_HOST_INTERFACE
int open(const char *pathname, unsigned flags, int mode) {
#else
int _open(const char *pathname, int flags, mode_t mode) {
#endif
    int fd = -1;
    bool is_sl;
    const char *fname = drop_dir(pathname, &is_sl);
    if (is_sl) {
#ifdef MG_FS_SLFS
        fd = fs_slfs_open(fname, flags, mode);
        if (fd >= 0) fd += SLFS_FD_BASE;
#endif
    }
    else {
#ifdef CC3200_FS_SPIFFS
        fd = fs_spiffs_open(fname, flags, mode);
        if (fd >= 0) fd += SPIFFS_FD_BASE;
#endif
    }
    LOG(LL_DEBUG,
        ("open(%s, 0x%x) = %d, fname = %s", pathname, flags, fd, fname));
    return fd;
}

int _stat(const char *pathname, struct stat *st) {
    int res = -1;
    bool is_sl;
    const char *fname = drop_dir(pathname, &is_sl);
    memset(st, 0, sizeof(*st));
    /* Simulate statting the root directory. */
    if (fname[0] == '\0' || strcmp(fname, ".") == 0) {
        st->st_ino = 0;
        st->st_mode = S_IFDIR | 0777;
        st->st_nlink = 1;
        st->st_size = 0;
        return 0;
    }
    if (is_sl) {
#ifdef MG_FS_SLFS
        res = fs_slfs_stat(fname, st);
#endif
    }
    else {
#ifdef CC3200_FS_SPIFFS
        res = fs_spiffs_stat(fname, st);
#endif
    }
    LOG(LL_DEBUG, ("stat(%s) = %d; fname = %s", pathname, res, fname));
    return res;
}

#if MG_TI_NO_HOST_INTERFACE
int close(int fd) {
#else
int _close(int fd) {
#endif
    int r = -1;
    switch (fd_type(fd)) {
    case FD_INVALID:
        r = set_errno(EBADF);
        break;
    case FD_SYS:
        r = set_errno(EACCES);
        break;
#ifdef CC3200_FS_SPIFFS
    case FD_SPIFFS:
        r = fs_spiffs_close(fd - SPIFFS_FD_BASE);
        break;
#endif
#ifdef MG_FS_SLFS
    case FD_SLFS:
        r = fs_slfs_close(fd - SLFS_FD_BASE);
        break;
#endif
    }
    DBG(("close(%d) = %d", fd, r));
    return r;
}

#if MG_TI_NO_HOST_INTERFACE
off_t lseek(int fd, off_t offset, int whence) {
#else
off_t _lseek(int fd, off_t offset, int whence) {
#endif
    int r = -1;
    switch (fd_type(fd)) {
    case FD_INVALID:
        r = set_errno(EBADF);
        break;
    case FD_SYS:
        r = set_errno(ESPIPE);
        break;
#ifdef CC3200_FS_SPIFFS
    case FD_SPIFFS:
        r = fs_spiffs_lseek(fd - SPIFFS_FD_BASE, offset, whence);
        break;
#endif
#ifdef MG_FS_SLFS
    case FD_SLFS:
        r = fs_slfs_lseek(fd - SLFS_FD_BASE, offset, whence);
        break;
#endif
    }
    DBG(("lseek(%d, %d, %d) = %d", fd, (int)offset, whence, r));
    return r;
}

int _fstat(int fd, struct stat *s) {
    int r = -1;
    memset(s, 0, sizeof(*s));
    switch (fd_type(fd)) {
    case FD_INVALID:
        r = set_errno(EBADF);
        break;
    case FD_SYS: {
        /* Create barely passable stats for STD{IN,OUT,ERR}. */
        memset(s, 0, sizeof(*s));
        s->st_ino = fd;
        s->st_mode = S_IFCHR | 0666;
        r = 0;
        break;
    }
#ifdef CC3200_FS_SPIFFS
    case FD_SPIFFS:
        r = fs_spiffs_fstat(fd - SPIFFS_FD_BASE, s);
        break;
#endif
#ifdef MG_FS_SLFS
    case FD_SLFS:
        r = fs_slfs_fstat(fd - SLFS_FD_BASE, s);
        break;
#endif
    }
    DBG(("fstat(%d) = %d", fd, r));
    return r;
}

#if MG_TI_NO_HOST_INTERFACE
int read(int fd, char *buf, unsigned count) {
#else
ssize_t _read(int fd, void *buf, size_t count) {
#endif
    int r = -1;
    switch (fd_type(fd)) {
    case FD_INVALID:
        r = set_errno(EBADF);
        break;
    case FD_SYS: {
        if (fd != 0) {
            r = set_errno(EACCES);
            break;
        }
        /* Should we allow reading from stdin = uart? */
        r = set_errno(ENOTSUP);
        break;
    }
#ifdef CC3200_FS_SPIFFS
    case FD_SPIFFS:
        r = fs_spiffs_read(fd - SPIFFS_FD_BASE, buf, count);
        break;
#endif
#ifdef MG_FS_SLFS
    case FD_SLFS:
        r = fs_slfs_read(fd - SLFS_FD_BASE, buf, count);
        break;
#endif
    }
    DBG(("read(%d, %u) = %d", fd, count, r));
    return r;
}

#if MG_TI_NO_HOST_INTERFACE
int write(int fd, const char *buf, unsigned count) {
#else
ssize_t _write(int fd, const void *buf, size_t count) {
#endif
    int r = -1;
    switch (fd_type(fd)) {
    case FD_INVALID:
        r = set_errno(EBADF);
        break;
    case FD_SYS: {
        if (fd == 0) {
            r = set_errno(EACCES);
            break;
        }
#ifdef MG_UART_WRITE
        MG_UART_WRITE(fd, buf, count);
#elif defined(MG_UART_CHAR_PUT)
        {
            size_t i;
            for (i = 0; i < count; i++) {
                const char c = ((const char *)buf)[i];
                if (c == '\n') MG_UART_CHAR_PUT(fd, '\r');
                MG_UART_CHAR_PUT(fd, c);
            }
        }
#endif
        r = count;
        break;
    }
#ifdef CC3200_FS_SPIFFS
    case FD_SPIFFS:
        r = fs_spiffs_write(fd - SPIFFS_FD_BASE, buf, count);
        break;
#endif
#ifdef MG_FS_SLFS
    case FD_SLFS:
        r = fs_slfs_write(fd - SLFS_FD_BASE, buf, count);
        break;
#endif
    }
    return r;
}

/*
 * On Newlib we override rename directly too, because the default
 * implementation using _link and _unlink doesn't work for us.
 */
#if MG_TI_NO_HOST_INTERFACE || defined(_NEWLIB_VERSION)
int rename(const char *frompath, const char *topath) {
    int r = -1;
    bool is_sl_from, is_sl_to;
    const char *from = drop_dir(frompath, &is_sl_from);
    const char *to = drop_dir(topath, &is_sl_to);
    if (is_sl_from || is_sl_to) {
        set_errno(ENOTSUP);
    }
    else {
#ifdef CC3200_FS_SPIFFS
        r = fs_spiffs_rename(from, to);
#endif
    }
    DBG(("rename(%s, %s) = %d", from, to, r));
    return r;
}
#endif /* MG_TI_NO_HOST_INTERFACE || defined(_NEWLIB_VERSION) */

#if MG_TI_NO_HOST_INTERFACE
int unlink(const char *pathname) {
#else
int _unlink(const char *pathname) {
#endif
    int r = -1;
    bool is_sl;
    const char *fname = drop_dir(pathname, &is_sl);
    if (is_sl) {
#ifdef MG_FS_SLFS
        r = fs_slfs_unlink(fname);
#endif
    }
    else {
#ifdef CC3200_FS_SPIFFS
        r = fs_spiffs_unlink(fname);
#endif
    }
    DBG(("unlink(%s) = %d, fname = %s", pathname, r, fname));
    return r;
}

#ifdef CC3200_FS_SPIFFS /* FailFS does not support listing files. */
DIR *opendir(const char *dir_name) {
    DIR *r = NULL;
    bool is_sl;
    drop_dir(dir_name, &is_sl);
    if (is_sl) {
        r = NULL;
        set_errno(ENOTSUP);
    }
    else {
        r = fs_spiffs_opendir(dir_name);
    }
    DBG(("opendir(%s) = %p", dir_name, r));
    return r;
}

struct dirent *readdir(DIR *dir) {
    struct dirent *res = fs_spiffs_readdir(dir);
    DBG(("readdir(%p) = %p", dir, res));
    return res;
}

int closedir(DIR *dir) {
    int res = fs_spiffs_closedir(dir);
    DBG(("closedir(%p) = %d", dir, res));
    return res;
}

int rmdir(const char *path) {
    return fs_spiffs_rmdir(path);
}

int mkdir(const char *path, mode_t mode) {
    (void)path;
    (void)mode;
    /* for spiffs supports only root dir, which comes from mongoose as '.' */
    return (strlen(path) == 1 && *path == '.') ? 0 : ENOTDIR;
}
#endif

int sl_fs_init(void) {
    int ret = 1;
#ifdef __TI_COMPILER_VERSION__
#ifdef MG_FS_SLFS
#pragma diag_push
#pragma diag_suppress 169 /* Nothing we can do about the prototype mismatch. \
                             */
    ret = (add_device("SL", _MSA, fs_slfs_open, fs_slfs_close, fs_slfs_read,
        fs_slfs_write, fs_slfs_lseek, fs_slfs_unlink,
        fs_slfs_rename) == 0);
#pragma diag_pop
#endif
#endif
    return ret;
}

#endif /* !defined(MG_FS_NO_VFS) */
#endif /* MG_NET_IF == MG_NET_IF_SIMPLELINK && (defined(MG_FS_SLFS) || \
          defined(MG_FS_SPIFFS)) */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/simplelink/sl_socket.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#if MG_NET_IF == MG_NET_IF_SIMPLELINK

#include <errno.h>
#include <stdio.h>

 /* Amalgamated: #include "common/platform.h" */

const char *inet_ntop(int af, const void *src, char *dst, socklen_t size) {
    int res;
    struct in_addr *in = (struct in_addr *) src;
    if (af != AF_INET) {
        errno = ENOTSUP;
        return NULL;
    }
    res = snprintf(dst, size, "%lu.%lu.%lu.%lu", SL_IPV4_BYTE(in->s_addr, 0),
        SL_IPV4_BYTE(in->s_addr, 1), SL_IPV4_BYTE(in->s_addr, 2),
        SL_IPV4_BYTE(in->s_addr, 3));
    return res > 0 ? dst : NULL;
}

char *inet_ntoa(struct in_addr n) {
    static char a[16];
    return (char *)inet_ntop(AF_INET, &n, a, sizeof(a));
}

int inet_pton(int af, const char *src, void *dst) {
    uint32_t a0, a1, a2, a3;
    uint8_t *db = (uint8_t *)dst;
    if (af != AF_INET) {
        errno = ENOTSUP;
        return 0;
    }
    if (sscanf(src, "%lu.%lu.%lu.%lu", &a0, &a1, &a2, &a3) != 4) {
        return 0;
    }
    *db = a3;
    *(db + 1) = a2;
    *(db + 2) = a1;
    *(db + 3) = a0;
    return 1;
}

#endif /* MG_NET_IF == MG_NET_IF_SIMPLELINK */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/simplelink/sl_mg_task.c"
#endif
#if MG_NET_IF == MG_NET_IF_SIMPLELINK && !defined(MG_SIMPLELINK_NO_OSI)

/* Amalgamated: #include "mg_task.h" */

#include <oslib/osi.h>

enum mg_q_msg_type {
    MG_Q_MSG_CB,
};
struct mg_q_msg {
    enum mg_q_msg_type type;
    void(*cb)(struct mg_mgr *mgr, void *arg);
    void *arg;
};
static OsiMsgQ_t s_mg_q;
static void mg_task(void *arg);

bool mg_start_task(int priority, int stack_size, mg_init_cb mg_init) {
    if (osi_MsgQCreate(&s_mg_q, "MG", sizeof(struct mg_q_msg), 16) != OSI_OK) {
        return false;
    }
    if (osi_TaskCreate(mg_task, (const signed char *) "MG", stack_size,
        (void *)mg_init, priority, NULL) != OSI_OK) {
        return false;
    }
    return true;
}

static void mg_task(void *arg) {
    struct mg_mgr mgr;
    mg_init_cb mg_init = (mg_init_cb)arg;
    mg_mgr_init(&mgr, NULL);
    mg_init(&mgr);
    while (1) {
        struct mg_q_msg msg;
        mg_mgr_poll(&mgr, 1);
        if (osi_MsgQRead(&s_mg_q, &msg, 1) != OSI_OK) continue;
        switch (msg.type) {
        case MG_Q_MSG_CB: {
            msg.cb(&mgr, msg.arg);
        }
        }
    }
}

void mg_run_in_task(void(*cb)(struct mg_mgr *mgr, void *arg), void *cb_arg) {
    struct mg_q_msg msg = { MG_Q_MSG_CB, cb, cb_arg };
    osi_MsgQWrite(&s_mg_q, &msg, OSI_NO_WAIT);
}

#endif /* MG_NET_IF == MG_NET_IF_SIMPLELINK && !defined(MG_SIMPLELINK_NO_OSI) \
          */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/simplelink/sl_net_if.h"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CS_COMMON_PLATFORMS_SIMPLELINK_SL_NET_IF_H_
#define CS_COMMON_PLATFORMS_SIMPLELINK_SL_NET_IF_H_

 /* Amalgamated: #include "mongoose/src/net_if.h" */

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#ifndef MG_ENABLE_NET_IF_SIMPLELINK
#define MG_ENABLE_NET_IF_SIMPLELINK MG_NET_IF == MG_NET_IF_SIMPLELINK
#endif

    extern const struct mg_iface_vtable mg_simplelink_iface_vtable;

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* CS_COMMON_PLATFORMS_SIMPLELINK_SL_NET_IF_H_ */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/simplelink/sl_net_if.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

 /* Amalgamated: #include "common/platforms/simplelink/sl_net_if.h" */

#if MG_ENABLE_NET_IF_SIMPLELINK

/* Amalgamated: #include "mongoose/src/internal.h" */
/* Amalgamated: #include "mongoose/src/util.h" */

#define MG_TCP_RECV_BUFFER_SIZE 1024
#define MG_UDP_RECV_BUFFER_SIZE 1500

static sock_t mg_open_listening_socket(struct mg_connection *nc,
    union socket_address *sa, int type,
    int proto);

static void mg_set_non_blocking_mode(sock_t sock) {
    SlSockNonblocking_t opt;
#if SL_MAJOR_VERSION_NUM < 2
    opt.NonblockingEnabled = 1;
#else
    opt.NonBlockingEnabled = 1;
#endif
    sl_SetSockOpt(sock, SL_SOL_SOCKET, SL_SO_NONBLOCKING, &opt, sizeof(opt));
}

static int mg_is_error(int n) {
    return (n < 0 && n != SL_ERROR_BSD_EALREADY && n != SL_ERROR_BSD_EAGAIN);
}

static void mg_sl_if_connect_tcp(struct mg_connection *nc,
    const union socket_address *sa) {
    int proto = 0;
#if MG_ENABLE_SSL && MG_SSL_IF == MG_SSL_IF_SIMPLELINK
    if (nc->flags & MG_F_SSL) proto = SL_SEC_SOCKET;
#endif
    sock_t sock = sl_Socket(AF_INET, SOCK_STREAM, proto);
    if (sock < 0) {
        nc->err = sock;
        goto out;
    }
    mg_sock_set(nc, sock);
#if MG_ENABLE_SSL && MG_SSL_IF == MG_SSL_IF_SIMPLELINK
    nc->err = sl_set_ssl_opts(sock, nc);
    if (nc->err != 0) goto out;
#endif
    nc->err = sl_Connect(sock, &sa->sa, sizeof(sa->sin));
out:
    DBG(("%p to %s:%d sock %d %d err %d", nc, inet_ntoa(sa->sin.sin_addr),
        ntohs(sa->sin.sin_port), nc->sock, proto, nc->err));
}

static void mg_sl_if_connect_udp(struct mg_connection *nc) {
    sock_t sock = sl_Socket(AF_INET, SOCK_DGRAM, 0);
    if (sock < 0) {
        nc->err = sock;
        return;
    }
    mg_sock_set(nc, sock);
    nc->err = 0;
}

static int mg_sl_if_listen_tcp(struct mg_connection *nc,
    union socket_address *sa) {
    int proto = 0;
    if (nc->flags & MG_F_SSL) proto = SL_SEC_SOCKET;
    sock_t sock = mg_open_listening_socket(nc, sa, SOCK_STREAM, proto);
    if (sock < 0) return sock;
    mg_sock_set(nc, sock);
    return 0;
}

static int mg_sl_if_listen_udp(struct mg_connection *nc,
    union socket_address *sa) {
    sock_t sock = mg_open_listening_socket(nc, sa, SOCK_DGRAM, 0);
    if (sock == INVALID_SOCKET) return (errno ? errno : 1);
    mg_sock_set(nc, sock);
    return 0;
}

static int mg_sl_if_tcp_send(struct mg_connection *nc, const void *buf,
    size_t len) {
    int n = (int)sl_Send(nc->sock, buf, len, 0);
    if (n < 0 && !mg_is_error(n)) n = 0;
    return n;
}

static int mg_sl_if_udp_send(struct mg_connection *nc, const void *buf,
    size_t len) {
    int n = sl_SendTo(nc->sock, buf, len, 0, &nc->sa.sa, sizeof(nc->sa.sin));
    if (n < 0 && !mg_is_error(n)) n = 0;
    return n;
}

static int mg_sl_if_tcp_recv(struct mg_connection *nc, void *buf, size_t len) {
    int n = sl_Recv(nc->sock, buf, len, 0);
    if (n == 0) {
        /* Orderly shutdown of the socket, try flushing output. */
        nc->flags |= MG_F_SEND_AND_CLOSE;
    }
    else if (n < 0 && !mg_is_error(n)) {
        n = 0;
    }
    return n;
}

static int mg_sl_if_udp_recv(struct mg_connection *nc, void *buf, size_t len,
    union socket_address *sa, size_t *sa_len) {
    SlSocklen_t sa_len_t = *sa_len;
    int n = sl_RecvFrom(nc->sock, buf, MG_UDP_RECV_BUFFER_SIZE, 0,
        (SlSockAddr_t *)sa, &sa_len_t);
    *sa_len = sa_len_t;
    if (n < 0 && !mg_is_error(n)) n = 0;
    return n;
}

static int mg_sl_if_create_conn(struct mg_connection *nc) {
    (void)nc;
    return 1;
}

void mg_sl_if_destroy_conn(struct mg_connection *nc) {
    if (nc->sock == INVALID_SOCKET) return;
    /* For UDP, only close outgoing sockets or listeners. */
    if (!(nc->flags & MG_F_UDP) || nc->listener == NULL) {
        sl_Close(nc->sock);
    }
    nc->sock = INVALID_SOCKET;
}

static int mg_accept_conn(struct mg_connection *lc) {
    struct mg_connection *nc;
    union socket_address sa;
    socklen_t sa_len = sizeof(sa);
    sock_t sock = sl_Accept(lc->sock, &sa.sa, &sa_len);
    if (sock < 0) {
        DBG(("%p: failed to accept: %d", lc, sock));
        return 0;
    }
    nc = mg_if_accept_new_conn(lc);
    if (nc == NULL) {
        sl_Close(sock);
        return 0;
    }
    DBG(("%p conn from %s:%d", nc, inet_ntoa(sa.sin.sin_addr),
        ntohs(sa.sin.sin_port)));
    mg_sock_set(nc, sock);
    mg_if_accept_tcp_cb(nc, &sa, sa_len);
    return 1;
}

/* 'sa' must be an initialized address to bind to */
static sock_t mg_open_listening_socket(struct mg_connection *nc,
    union socket_address *sa, int type,
    int proto) {
    int r;
    socklen_t sa_len =
        (sa->sa.sa_family == AF_INET) ? sizeof(sa->sin) : sizeof(sa->sin6);
    sock_t sock = sl_Socket(sa->sa.sa_family, type, proto);
    if (sock < 0) return sock;
#if MG_ENABLE_SSL && MG_SSL_IF == MG_SSL_IF_SIMPLELINK
    if ((r = sl_set_ssl_opts(sock, nc)) < 0) goto clean;
#endif
    if ((r = sl_Bind(sock, &sa->sa, sa_len)) < 0) goto clean;
    if (type != SOCK_DGRAM) {
        if ((r = sl_Listen(sock, SOMAXCONN)) < 0) goto clean;
    }
    mg_set_non_blocking_mode(sock);
clean:
    if (r < 0) {
        sl_Close(sock);
        sock = r;
    }
    return sock;
}

#define _MG_F_FD_CAN_READ 1
#define _MG_F_FD_CAN_WRITE 1 << 1
#define _MG_F_FD_ERROR 1 << 2

void mg_mgr_handle_conn(struct mg_connection *nc, int fd_flags, double now) {
    DBG(("%p fd=%d fd_flags=%d nc_flags=0x%lx rmbl=%d smbl=%d", nc, nc->sock,
        fd_flags, nc->flags, (int)nc->recv_mbuf.len, (int)nc->send_mbuf.len));

    if (!mg_if_poll(nc, now)) return;

    if (nc->flags & MG_F_CONNECTING) {
        if ((nc->flags & MG_F_UDP) || nc->err != SL_ERROR_BSD_EALREADY) {
            mg_if_connect_cb(nc, nc->err);
        }
        else {
            /* In SimpleLink, to get status of non-blocking connect() we need to wait
             * until socket is writable and repeat the call to sl_Connect again,
             * which will now return the real status. */
            if (fd_flags & _MG_F_FD_CAN_WRITE) {
                nc->err = sl_Connect(nc->sock, &nc->sa.sa, sizeof(nc->sa.sin));
                DBG(("%p conn res=%d", nc, nc->err));
                if (nc->err == SL_ERROR_BSD_ESECSNOVERIFY ||
                    /* TODO(rojer): Provide API to set the date for verification. */
                    nc->err == SL_ERROR_BSD_ESECDATEERROR
#if SL_MAJOR_VERSION_NUM >= 2
                    /* Per SWRU455, this error does not mean verification failed,
                     * it only means that the cert used is not present in the trusted
                     * root CA catalog. Which is perfectly fine. */
                    ||
                    nc->err == SL_ERROR_BSD_ESECUNKNOWNROOTCA
#endif
                    ) {
                    nc->err = 0;
                }
                mg_if_connect_cb(nc, nc->err);
            }
        }
        /* Ignore read/write in further processing, we've handled it. */
        fd_flags &= ~(_MG_F_FD_CAN_READ | _MG_F_FD_CAN_WRITE);
    }

    if (fd_flags & _MG_F_FD_CAN_READ) {
        if (nc->flags & MG_F_UDP) {
            mg_if_can_recv_cb(nc);
        }
        else {
            if (nc->flags & MG_F_LISTENING) {
                mg_accept_conn(nc);
            }
            else {
                mg_if_can_recv_cb(nc);
            }
        }
    }

    if (fd_flags & _MG_F_FD_CAN_WRITE) {
        mg_if_can_send_cb(nc);
    }

    DBG(("%p after fd=%d nc_flags=0x%lx rmbl=%d smbl=%d", nc, nc->sock, nc->flags,
        (int)nc->recv_mbuf.len, (int)nc->send_mbuf.len));
}

/* Associate a socket to a connection. */
void mg_sl_if_sock_set(struct mg_connection *nc, sock_t sock) {
    mg_set_non_blocking_mode(sock);
    nc->sock = sock;
    DBG(("%p %d", nc, sock));
}

void mg_sl_if_init(struct mg_iface *iface) {
    (void)iface;
    DBG(("%p using sl_Select()", iface->mgr));
}

void mg_sl_if_free(struct mg_iface *iface) {
    (void)iface;
}

void mg_sl_if_add_conn(struct mg_connection *nc) {
    (void)nc;
}

void mg_sl_if_remove_conn(struct mg_connection *nc) {
    (void)nc;
}

time_t mg_sl_if_poll(struct mg_iface *iface, int timeout_ms) {
    struct mg_mgr *mgr = iface->mgr;
    double now = mg_time();
    double min_timer;
    struct mg_connection *nc, *tmp;
    struct SlTimeval_t tv;
    SlFdSet_t read_set, write_set, err_set;
    sock_t max_fd = INVALID_SOCKET;
    int num_fds, num_ev = 0, num_timers = 0;

    SL_SOCKET_FD_ZERO(&read_set);
    SL_SOCKET_FD_ZERO(&write_set);
    SL_SOCKET_FD_ZERO(&err_set);

    /*
     * Note: it is ok to have connections with sock == INVALID_SOCKET in the list,
     * e.g. timer-only "connections".
     */
    min_timer = 0;
    for (nc = mgr->active_connections, num_fds = 0; nc != NULL; nc = tmp) {
        tmp = nc->next;

        if (nc->sock != INVALID_SOCKET) {
            num_fds++;

            if (!(nc->flags & MG_F_WANT_WRITE) &&
                nc->recv_mbuf.len < nc->recv_mbuf_limit &&
                (!(nc->flags & MG_F_UDP) || nc->listener == NULL)) {
                SL_SOCKET_FD_SET(nc->sock, &read_set);
                if (max_fd == INVALID_SOCKET || nc->sock > max_fd) max_fd = nc->sock;
            }

            if (((nc->flags & MG_F_CONNECTING) && !(nc->flags & MG_F_WANT_READ)) ||
                (nc->send_mbuf.len > 0 && !(nc->flags & MG_F_CONNECTING))) {
                SL_SOCKET_FD_SET(nc->sock, &write_set);
                SL_SOCKET_FD_SET(nc->sock, &err_set);
                if (max_fd == INVALID_SOCKET || nc->sock > max_fd) max_fd = nc->sock;
            }
        }

        if (nc->ev_timer_time > 0) {
            if (num_timers == 0 || nc->ev_timer_time < min_timer) {
                min_timer = nc->ev_timer_time;
            }
            num_timers++;
        }
    }

    /*
     * If there is a timer to be fired earlier than the requested timeout,
     * adjust the timeout.
     */
    if (num_timers > 0) {
        double timer_timeout_ms = (min_timer - mg_time()) * 1000 + 1 /* rounding */;
        if (timer_timeout_ms < timeout_ms) {
            timeout_ms = timer_timeout_ms;
        }
    }
    if (timeout_ms < 0) timeout_ms = 0;

    tv.tv_sec = timeout_ms / 1000;
    tv.tv_usec = (timeout_ms % 1000) * 1000;

    if (num_fds > 0) {
        num_ev = sl_Select((int)max_fd + 1, &read_set, &write_set, &err_set, &tv);
    }

    now = mg_time();
    DBG(("sl_Select @ %ld num_ev=%d of %d, timeout=%d", (long)now, num_ev,
        num_fds, timeout_ms));

    for (nc = mgr->active_connections; nc != NULL; nc = tmp) {
        int fd_flags = 0;
        if (nc->sock != INVALID_SOCKET) {
            if (num_ev > 0) {
                fd_flags =
                    (SL_SOCKET_FD_ISSET(nc->sock, &read_set) &&
                    (!(nc->flags & MG_F_UDP) || nc->listener == NULL)
                        ? _MG_F_FD_CAN_READ
                        : 0) |
                        (SL_SOCKET_FD_ISSET(nc->sock, &write_set) ? _MG_F_FD_CAN_WRITE
                            : 0) |
                            (SL_SOCKET_FD_ISSET(nc->sock, &err_set) ? _MG_F_FD_ERROR : 0);
            }
            /* SimpleLink does not report UDP sockets as writable. */
            if (nc->flags & MG_F_UDP && nc->send_mbuf.len > 0) {
                fd_flags |= _MG_F_FD_CAN_WRITE;
            }
        }
        tmp = nc->next;
        mg_mgr_handle_conn(nc, fd_flags, now);
    }

    return now;
}

void mg_sl_if_get_conn_addr(struct mg_connection *nc, int remote,
    union socket_address *sa) {
    /* SimpleLink does not provide a way to get socket's peer address after
     * accept or connect. Address should have been preserved in the connection,
     * so we do our best here by using it. */
    if (remote) memcpy(sa, &nc->sa, sizeof(*sa));
}

void sl_restart_cb(struct mg_mgr *mgr) {
    /*
     * SimpleLink has been restarted, meaning all sockets have been invalidated.
     * We try our best - we'll restart the listeners, but for outgoing
     * connections we have no option but to terminate.
     */
    struct mg_connection *nc;
    for (nc = mg_next(mgr, NULL); nc != NULL; nc = mg_next(mgr, nc)) {
        if (nc->sock == INVALID_SOCKET) continue; /* Could be a timer */
        if (nc->flags & MG_F_LISTENING) {
            DBG(("restarting %p %s:%d", nc, inet_ntoa(nc->sa.sin.sin_addr),
                ntohs(nc->sa.sin.sin_port)));
            int res = (nc->flags & MG_F_UDP ? mg_sl_if_listen_udp(nc, &nc->sa)
                : mg_sl_if_listen_tcp(nc, &nc->sa));
            if (res == 0) continue;
            /* Well, we tried and failed. Fall through to closing. */
        }
        nc->sock = INVALID_SOCKET;
        DBG(("terminating %p %s:%d", nc, inet_ntoa(nc->sa.sin.sin_addr),
            ntohs(nc->sa.sin.sin_port)));
        /* TODO(rojer): Outgoing UDP? */
        nc->flags |= MG_F_CLOSE_IMMEDIATELY;
    }
}

/* clang-format off */
#define MG_SL_IFACE_VTABLE                                              \
  {                                                                     \
    mg_sl_if_init,                                                      \
    mg_sl_if_free,                                                      \
    mg_sl_if_add_conn,                                                  \
    mg_sl_if_remove_conn,                                               \
    mg_sl_if_poll,                                                      \
    mg_sl_if_listen_tcp,                                                \
    mg_sl_if_listen_udp,                                                \
    mg_sl_if_connect_tcp,                                               \
    mg_sl_if_connect_udp,                                               \
    mg_sl_if_tcp_send,                                                  \
    mg_sl_if_udp_send,                                                  \
    mg_sl_if_tcp_recv,                                                  \
    mg_sl_if_udp_recv,                                                  \
    mg_sl_if_create_conn,                                               \
    mg_sl_if_destroy_conn,                                              \
    mg_sl_if_sock_set,                                                  \
    mg_sl_if_get_conn_addr,                                             \
  }
/* clang-format on */

const struct mg_iface_vtable mg_simplelink_iface_vtable = MG_SL_IFACE_VTABLE;
#if MG_NET_IF == MG_NET_IF_SIMPLELINK
const struct mg_iface_vtable mg_default_iface_vtable = MG_SL_IFACE_VTABLE;
#endif

#endif /* MG_ENABLE_NET_IF_SIMPLELINK */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/simplelink/sl_ssl_if.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#if MG_ENABLE_SSL && MG_SSL_IF == MG_SSL_IF_SIMPLELINK

 /* Amalgamated: #include "common/mg_mem.h" */

#ifndef MG_SSL_IF_SIMPLELINK_SLFS_PREFIX
#define MG_SSL_IF_SIMPLELINK_SLFS_PREFIX "SL:"
#endif

#define MG_SSL_IF_SIMPLELINK_SLFS_PREFIX_LEN \
  (sizeof(MG_SSL_IF_SIMPLELINK_SLFS_PREFIX) - 1)

struct mg_ssl_if_ctx {
    char *ssl_cert;
    char *ssl_key;
    char *ssl_ca_cert;
    char *ssl_server_name;
};

void mg_ssl_if_init() {
}

enum mg_ssl_if_result mg_ssl_if_conn_init(
    struct mg_connection *nc, const struct mg_ssl_if_conn_params *params,
    const char **err_msg) {
    struct mg_ssl_if_ctx *ctx =
        (struct mg_ssl_if_ctx *) MG_CALLOC(1, sizeof(*ctx));
    if (ctx == NULL) {
        MG_SET_PTRPTR(err_msg, "Out of memory");
        return MG_SSL_ERROR;
    }
    nc->ssl_if_data = ctx;

    if (params->cert != NULL || params->key != NULL) {
        if (params->cert != NULL && params->key != NULL) {
            ctx->ssl_cert = strdup(params->cert);
            ctx->ssl_key = strdup(params->key);
        }
        else {
            MG_SET_PTRPTR(err_msg, "Both cert and key are required.");
            return MG_SSL_ERROR;
        }
    }
    if (params->ca_cert != NULL && strcmp(params->ca_cert, "*") != 0) {
        ctx->ssl_ca_cert = strdup(params->ca_cert);
    }
    /* TODO(rojer): cipher_suites. */
    if (params->server_name != NULL) {
        ctx->ssl_server_name = strdup(params->server_name);
    }
    return MG_SSL_OK;
}

enum mg_ssl_if_result mg_ssl_if_conn_accept(struct mg_connection *nc,
    struct mg_connection *lc) {
    /* SimpleLink does everything for us, nothing for us to do. */
    (void)nc;
    (void)lc;
    return MG_SSL_OK;
}

enum mg_ssl_if_result mg_ssl_if_handshake(struct mg_connection *nc) {
    /* SimpleLink has already performed the handshake, nothing to do. */
    return MG_SSL_OK;
}

int mg_ssl_if_read(struct mg_connection *nc, void *buf, size_t len) {
    /* SimpelLink handles TLS, so this is just a pass-through. */
    int n = nc->iface->vtable->tcp_recv(nc, buf, len);
    if (n == 0) nc->flags |= MG_F_WANT_READ;
    return n;
}

int mg_ssl_if_write(struct mg_connection *nc, const void *buf, size_t len) {
    /* SimpelLink handles TLS, so this is just a pass-through. */
    return nc->iface->vtable->tcp_send(nc, buf, len);
}

void mg_ssl_if_conn_close_notify(struct mg_connection *nc) {
    /* Nothing to do */
    (void)nc;
}

void mg_ssl_if_conn_free(struct mg_connection *nc) {
    struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    if (ctx == NULL) return;
    nc->ssl_if_data = NULL;
    MG_FREE(ctx->ssl_cert);
    MG_FREE(ctx->ssl_key);
    MG_FREE(ctx->ssl_ca_cert);
    MG_FREE(ctx->ssl_server_name);
    memset(ctx, 0, sizeof(*ctx));
    MG_FREE(ctx);
}

bool pem_to_der(const char *pem_file, const char *der_file) {
    bool ret = false;
    FILE *pf = NULL, *df = NULL;
    bool writing = false;
    pf = fopen(pem_file, "r");
    if (pf == NULL) goto clean;
    remove(der_file);
    fs_slfs_set_file_size(der_file + MG_SSL_IF_SIMPLELINK_SLFS_PREFIX_LEN, 2048);
    df = fopen(der_file, "w");
    fs_slfs_unset_file_flags(der_file + MG_SSL_IF_SIMPLELINK_SLFS_PREFIX_LEN);
    if (df == NULL) goto clean;
    while (1) {
        char pem_buf[70];
        char der_buf[48];
        if (!fgets(pem_buf, sizeof(pem_buf), pf)) break;
        if (writing) {
            if (strstr(pem_buf, "-----END ") != NULL) {
                ret = true;
                break;
            }
            int l = 0;
            while (!isspace((unsigned int)pem_buf[l])) l++;
            int der_len = 0;
            cs_base64_decode((const unsigned char *)pem_buf, sizeof(pem_buf),
                der_buf, &der_len);
            if (der_len <= 0) break;
            if (fwrite(der_buf, 1, der_len, df) != der_len) break;
        }
        else if (strstr(pem_buf, "-----BEGIN ") != NULL) {
            writing = true;
        }
    }

clean:
    if (pf != NULL) fclose(pf);
    if (df != NULL) {
        fclose(df);
        if (!ret) remove(der_file);
    }
    return ret;
}

#if MG_ENABLE_FILESYSTEM && defined(MG_FS_SLFS)
/* If the file's extension is .pem, convert it to DER format and put on SLFS. */
static char *sl_pem2der(const char *pem_file) {
    const char *pem_ext = strstr(pem_file, ".pem");
    if (pem_ext == NULL || *(pem_ext + 4) != '\0') {
        return strdup(pem_file);
    }
    char *der_file = NULL;
    /* DER file must be located on SLFS, add prefix. */
    int l = mg_asprintf(&der_file, 0, MG_SSL_IF_SIMPLELINK_SLFS_PREFIX "%.*s.der",
        (int)(pem_ext - pem_file), pem_file);
    if (der_file == NULL) return NULL;
    bool result = false;
    cs_stat_t st;
    if (mg_stat(der_file, &st) != 0) {
        result = pem_to_der(pem_file, der_file);
        LOG(LL_DEBUG, ("%s -> %s = %d", pem_file, der_file, result));
    }
    else {
        /* File exists, assume it's already been converted. */
        result = true;
    }
    if (result) {
        /* Strip the SL: prefix we added since NWP does not expect it. */
        memmove(der_file, der_file + MG_SSL_IF_SIMPLELINK_SLFS_PREFIX_LEN,
            l - 2 /* including \0 */);
    }
    else {
        MG_FREE(der_file);
        der_file = NULL;
    }
    return der_file;
}
#else
static char *sl_pem2der(const char *pem_file) {
    return strdup(pem_file);
}
#endif

int sl_set_ssl_opts(int sock, struct mg_connection *nc) {
    int err;
    const struct mg_ssl_if_ctx *ctx = (struct mg_ssl_if_ctx *) nc->ssl_if_data;
    DBG(("%p ssl ctx: %p", nc, ctx));

    if (ctx == NULL) return 0;
    DBG(("%p %s,%s,%s,%s", nc, (ctx->ssl_cert ? ctx->ssl_cert : "-"),
        (ctx->ssl_key ? ctx->ssl_cert : "-"),
        (ctx->ssl_ca_cert ? ctx->ssl_ca_cert : "-"),
        (ctx->ssl_server_name ? ctx->ssl_server_name : "-")));
    if (ctx->ssl_cert != NULL && ctx->ssl_key != NULL) {
        char *ssl_cert = sl_pem2der(ctx->ssl_cert), *ssl_key = NULL;
        if (ssl_cert != NULL) {
            err = sl_SetSockOpt(sock, SL_SOL_SOCKET,
                SL_SO_SECURE_FILES_CERTIFICATE_FILE_NAME, ssl_cert,
                strlen(ssl_cert));
            MG_FREE(ssl_cert);
            LOG(LL_DEBUG, ("CERTIFICATE_FILE_NAME %s -> %d", ssl_cert, err));
            ssl_key = sl_pem2der(ctx->ssl_key);
            if (ssl_key != NULL) {
                err = sl_SetSockOpt(sock, SL_SOL_SOCKET,
                    SL_SO_SECURE_FILES_PRIVATE_KEY_FILE_NAME, ssl_key,
                    strlen(ssl_key));
                MG_FREE(ssl_key);
                LOG(LL_DEBUG, ("PRIVATE_KEY_FILE_NAME %s -> %d", ssl_key, err));
            }
            else {
                err = -1;
            }
        }
        else {
            err = -1;
        }
        if (err != 0) return err;
    }
    if (ctx->ssl_ca_cert != NULL) {
        if (ctx->ssl_ca_cert[0] != '\0') {
            char *ssl_ca_cert = sl_pem2der(ctx->ssl_ca_cert);
            if (ssl_ca_cert != NULL) {
                err =
                    sl_SetSockOpt(sock, SL_SOL_SOCKET, SL_SO_SECURE_FILES_CA_FILE_NAME,
                        ssl_ca_cert, strlen(ssl_ca_cert));
                LOG(LL_DEBUG, ("CA_FILE_NAME %s -> %d", ssl_ca_cert, err));
            }
            else {
                err = -1;
            }
            MG_FREE(ssl_ca_cert);
            if (err != 0) return err;
        }
    }
    if (ctx->ssl_server_name != NULL) {
        err = sl_SetSockOpt(sock, SL_SOL_SOCKET,
            SL_SO_SECURE_DOMAIN_NAME_VERIFICATION,
            ctx->ssl_server_name, strlen(ctx->ssl_server_name));
        DBG(("DOMAIN_NAME_VERIFICATION %s -> %d", ctx->ssl_server_name, err));
        /* Domain name verificationw as added in a NWP service pack, older
         * versions return SL_ERROR_BSD_ENOPROTOOPT. There isn't much we can do
         * about it,
         * so we ignore the error. */
        if (err != 0 && err != SL_ERROR_BSD_ENOPROTOOPT) return err;
    }
    return 0;
}

#endif /* MG_ENABLE_SSL && MG_SSL_IF == MG_SSL_IF_SIMPLELINK */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/lwip/mg_lwip_net_if.h"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CS_COMMON_PLATFORMS_LWIP_MG_NET_IF_LWIP_H_
#define CS_COMMON_PLATFORMS_LWIP_MG_NET_IF_LWIP_H_

#ifndef MG_ENABLE_NET_IF_LWIP_LOW_LEVEL
#define MG_ENABLE_NET_IF_LWIP_LOW_LEVEL MG_NET_IF == MG_NET_IF_LWIP_LOW_LEVEL
#endif

#if MG_ENABLE_NET_IF_LWIP_LOW_LEVEL

#include <stdint.h>

extern const struct mg_iface_vtable mg_lwip_iface_vtable;

struct mg_lwip_conn_state {
    struct mg_connection *nc;
    struct mg_connection *lc;
    union {
        struct tcp_pcb *tcp;
        struct udp_pcb *udp;
    } pcb;
    err_t err;
    size_t num_sent; /* Number of acknowledged bytes to be reported to the core */
    struct pbuf *rx_chain; /* Chain of incoming data segments. */
    size_t rx_offset; /* Offset within the first pbuf (if partially consumed) */
    /* Last SSL write size, for retries. */
    int last_ssl_write_size;
    /* Whether MG_SIG_RECV is already pending for this connection */
    int recv_pending;
    /* Whether the connection is about to close, just `rx_chain` needs to drain */
    int draining_rx_chain;
};

enum mg_sig_type {
    MG_SIG_CONNECT_RESULT = 1,
    MG_SIG_RECV = 2,
    MG_SIG_CLOSE_CONN = 3,
    MG_SIG_TOMBSTONE = 4,
    MG_SIG_ACCEPT = 5,
};

void mg_lwip_post_signal(enum mg_sig_type sig, struct mg_connection *nc);

/* To be implemented by the platform. */
void mg_lwip_mgr_schedule_poll(struct mg_mgr *mgr);

#endif /* MG_ENABLE_NET_IF_LWIP_LOW_LEVEL */

#endif /* CS_COMMON_PLATFORMS_LWIP_MG_NET_IF_LWIP_H_ */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/lwip/mg_lwip_net_if.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#if MG_ENABLE_NET_IF_LWIP_LOW_LEVEL

 /* Amalgamated: #include "common/mg_mem.h" */

#include <lwip/init.h>
#include <lwip/pbuf.h>
#include <lwip/tcp.h>
#include <lwip/tcpip.h>
#if ((LWIP_VERSION_MAJOR << 8) | LWIP_VERSION_MINOR) >= 0x0105
#include <lwip/priv/tcp_priv.h>   /* For tcp_seg */
#include <lwip/priv/tcpip_priv.h> /* For tcpip_api_call */
#else
#include <lwip/tcp_impl.h>
#endif
#include <lwip/udp.h>

/* Amalgamated: #include "common/cs_dbg.h" */

/*
 * Newest versions of LWIP have ip_2_ip4, older have ipX_2_ip,
 * even older have nothing.
 */
#ifndef ip_2_ip4
#ifdef ipX_2_ip
#define ip_2_ip4(addr) ipX_2_ip(addr)
#else
#define ip_2_ip4(addr) (addr)
#endif
#endif

 /*
  * Depending on whether Mongoose is compiled with ipv6 support, use right
  * lwip functions
  */
#if MG_ENABLE_IPV6
#define TCP_NEW tcp_new_ip6
#define TCP_BIND tcp_bind_ip6
#define UDP_BIND udp_bind_ip6
#define IPADDR_NTOA(x) ip6addr_ntoa((const ip6_addr_t *)(x))
#define SET_ADDR(dst, src)                               \
  memcpy((dst)->sin6.sin6_addr.s6_addr, (src)->ip6.addr, \
         sizeof((dst)->sin6.sin6_addr.s6_addr))
#else
#define TCP_NEW tcp_new
#define TCP_BIND tcp_bind
#define UDP_BIND udp_bind
#define IPADDR_NTOA ipaddr_ntoa
#define SET_ADDR(dst, src) (dst)->sin.sin_addr.s_addr = ip_2_ip4(src)->addr
#endif

#if !NO_SYS
#if LWIP_TCPIP_CORE_LOCKING
  /* With locking tcpip_api_call is just a function call wrapped in lock/unlock,
   * so we can get away with just casting. */
void mg_lwip_netif_run_on_tcpip(void(*fn)(void *), void *arg) {
    tcpip_api_call((tcpip_api_call_fn)fn, (struct tcpip_api_call_data *) arg);
}
#else
static sys_sem_t s_tcpip_call_lock_sem = NULL;
static sys_sem_t s_tcpip_call_sync_sem = NULL;
struct mg_lwip_netif_tcpip_call_ctx {
    void(*fn)(void *);
    void *arg;
};
static void xxx_tcpip(void *arg) {
    struct mg_lwip_netif_tcpip_call_ctx *ctx =
        (struct mg_lwip_netif_tcpip_call_ctx *) arg;
    ctx->fn(ctx->arg);
    sys_sem_signal(&s_tcpip_call_sync_sem);
}
void mg_lwip_netif_run_on_tcpip(void(*fn)(void *), void *arg) {
    struct mg_lwip_netif_tcpip_call_ctx ctx = { .fn = fn,.arg = arg };
    sys_arch_sem_wait(&s_tcpip_call_lock_sem, 0);
    tcpip_send_msg_wait_sem(xxx_tcpip, &ctx, &s_tcpip_call_sync_sem);
    sys_sem_signal(&s_tcpip_call_lock_sem);
}
#endif
#else
#define mg_lwip_netif_run_on_tcpip(fn, arg) (fn)(arg)
#endif

void mg_lwip_if_init(struct mg_iface *iface);
void mg_lwip_if_free(struct mg_iface *iface);
void mg_lwip_if_add_conn(struct mg_connection *nc);
void mg_lwip_if_remove_conn(struct mg_connection *nc);
time_t mg_lwip_if_poll(struct mg_iface *iface, int timeout_ms);

// If compiling for Mongoose OS.
#ifdef MGOS
extern void mgos_lock();
extern void mgos_unlock();
#else
#define mgos_lock()
#define mgos_unlock()
#endif

static void mg_lwip_recv_common(struct mg_connection *nc, struct pbuf *p);

#if LWIP_TCP_KEEPALIVE
void mg_lwip_set_keepalive_params(struct mg_connection *nc, int idle,
    int interval, int count) {
    if (nc->sock == INVALID_SOCKET || nc->flags & MG_F_UDP) {
        return;
    }
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    struct tcp_pcb *tpcb = cs->pcb.tcp;
    if (idle > 0 && interval > 0 && count > 0) {
        tpcb->keep_idle = idle * 1000;
        tpcb->keep_intvl = interval * 1000;
        tpcb->keep_cnt = count;
        tpcb->so_options |= SOF_KEEPALIVE;
    }
    else {
        tpcb->so_options &= ~SOF_KEEPALIVE;
    }
}
#elif !defined(MG_NO_LWIP_TCP_KEEPALIVE)
#warning LWIP TCP keepalive is disabled.Please consider enabling it.
#endif /* LWIP_TCP_KEEPALIVE */

static err_t mg_lwip_tcp_conn_cb(void *arg, struct tcp_pcb *tpcb, err_t err) {
    struct mg_connection *nc = (struct mg_connection *) arg;
    DBG(("%p connect to %s:%u = %d", nc, IPADDR_NTOA(ipX_2_ip(&tpcb->remote_ip)),
        tpcb->remote_port, err));
    if (nc == NULL) {
        tcp_abort(tpcb);
        return ERR_ARG;
    }
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    cs->err = err;
#if LWIP_TCP_KEEPALIVE
    if (err == 0) mg_lwip_set_keepalive_params(nc, 60, 10, 6);
#endif
    mg_lwip_post_signal(MG_SIG_CONNECT_RESULT, nc);
    return ERR_OK;
}

static void mg_lwip_tcp_error_cb(void *arg, err_t err) {
    struct mg_connection *nc = (struct mg_connection *) arg;
    DBG(("%p conn error %d", nc, err));
    if (nc == NULL || (nc->flags & MG_F_CLOSE_IMMEDIATELY)) return;
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    cs->pcb.tcp = NULL; /* Has already been deallocated */
    if (nc->flags & MG_F_CONNECTING) {
        cs->err = err;
        mg_lwip_post_signal(MG_SIG_CONNECT_RESULT, nc);
    }
    else {
        mg_lwip_post_signal(MG_SIG_CLOSE_CONN, nc);
    }
}

static err_t mg_lwip_tcp_recv_cb(void *arg, struct tcp_pcb *tpcb,
    struct pbuf *p, err_t err) {
    struct mg_connection *nc = (struct mg_connection *) arg;
    struct mg_lwip_conn_state *cs =
        (nc ? (struct mg_lwip_conn_state *) nc->sock : NULL);
    DBG(("%p %p %p %p %u %d", nc, cs, tpcb, p, (p != NULL ? p->tot_len : 0),
        err));
    if (p == NULL) {
        if (nc != NULL && !(nc->flags & MG_F_CLOSE_IMMEDIATELY)) {
            if (cs->rx_chain != NULL) {
                /*
                 * rx_chain still contains non-consumed data, don't close the
                 * connection
                 */
                cs->draining_rx_chain = 1;
            }
            else {
                mg_lwip_post_signal(MG_SIG_CLOSE_CONN, nc);
            }
        }
        else {
            /* Tombstoned connection, do nothing. */
        }
        return ERR_OK;
    }
    else if (nc == NULL) {
        tcp_abort(tpcb);
        return ERR_ARG;
    }
    /*
     * If we get a chain of more than one segment at once, we need to bump
     * refcount on the subsequent bufs to make them independent.
     */
    if (p->next != NULL) {
        struct pbuf *q = p->next;
        for (; q != NULL; q = q->next) pbuf_ref(q);
    }
    mgos_lock();
    if (cs->rx_chain == NULL) {
        cs->rx_offset = 0;
    }
    else if (pbuf_clen(cs->rx_chain) >= 4) {
        /* ESP SDK has a limited pool of 5 pbufs. We must not hog them all or RX
         * will be completely blocked. We already have at least 4 in the chain,
         * this one is the last, so we have to make a copy and release this one. */
        struct pbuf *np = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
        if (np != NULL) {
            pbuf_copy(np, p);
            pbuf_free(p);
            p = np;
        }
    }
    mg_lwip_recv_common(nc, p);
    mgos_unlock();
    (void)err;
    return ERR_OK;
}

static err_t mg_lwip_tcp_sent_cb(void *arg, struct tcp_pcb *tpcb,
    u16_t num_sent) {
    struct mg_connection *nc = (struct mg_connection *) arg;
    DBG(("%p %p %u %p %p", nc, tpcb, num_sent, tpcb->unsent, tpcb->unacked));
    if (nc == NULL) return ERR_OK;
    if ((nc->flags & MG_F_SEND_AND_CLOSE) && !(nc->flags & MG_F_WANT_WRITE) &&
        nc->send_mbuf.len == 0 && tpcb->unsent == NULL && tpcb->unacked == NULL) {
        mg_lwip_post_signal(MG_SIG_CLOSE_CONN, nc);
    }
    if (nc->send_mbuf.len > 0 || (nc->flags & MG_F_WANT_WRITE)) {
        mg_lwip_mgr_schedule_poll(nc->mgr);
    }
    (void)num_sent;
    return ERR_OK;
}

struct mg_lwip_if_connect_tcp_ctx {
    struct mg_connection *nc;
    const union socket_address *sa;
};

static void mg_lwip_if_connect_tcp_tcpip(void *arg) {
    struct mg_lwip_if_connect_tcp_ctx *ctx =
        (struct mg_lwip_if_connect_tcp_ctx *) arg;
    struct mg_connection *nc = ctx->nc;
    const union socket_address *sa = ctx->sa;

    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    struct tcp_pcb *tpcb = TCP_NEW();
    cs->pcb.tcp = tpcb;
    ip_addr_t *ip = (ip_addr_t *)&sa->sin.sin_addr.s_addr;
    u16_t port = ntohs(sa->sin.sin_port);
    tcp_arg(tpcb, nc);
    tcp_err(tpcb, mg_lwip_tcp_error_cb);
    tcp_sent(tpcb, mg_lwip_tcp_sent_cb);
    tcp_recv(tpcb, mg_lwip_tcp_recv_cb);
    cs->err = TCP_BIND(tpcb, IP_ADDR_ANY, 0 /* any port */);
    DBG(("%p tcp_bind = %d", nc, cs->err));
    if (cs->err != ERR_OK) {
        mg_lwip_post_signal(MG_SIG_CONNECT_RESULT, nc);
        return;
    }
    cs->err = tcp_connect(tpcb, ip, port, mg_lwip_tcp_conn_cb);
    DBG(("%p tcp_connect %p = %d", nc, tpcb, cs->err));
    if (cs->err != ERR_OK) {
        mg_lwip_post_signal(MG_SIG_CONNECT_RESULT, nc);
        return;
    }
}

void mg_lwip_if_connect_tcp(struct mg_connection *nc,
    const union socket_address *sa) {
    struct mg_lwip_if_connect_tcp_ctx ctx = { .nc = nc,.sa = sa };
    mg_lwip_netif_run_on_tcpip(mg_lwip_if_connect_tcp_tcpip, &ctx);
}

/*
 * Lwip included in the SDKs for nRF5x chips has different type for the
 * callback of `udp_recv()`
 */
#if ((LWIP_VERSION_MAJOR << 8) | LWIP_VERSION_MINOR) >= 0x0105
static void mg_lwip_udp_recv_cb(void *arg, struct udp_pcb *pcb, struct pbuf *p,
    const ip_addr_t *addr, u16_t port)
#else
static void mg_lwip_udp_recv_cb(void *arg, struct udp_pcb *pcb, struct pbuf *p,
    ip_addr_t *addr, u16_t port)
#endif
{
    struct mg_connection *nc = (struct mg_connection *) arg;
    DBG(("%p %s:%u %p %u %u", nc, IPADDR_NTOA(addr), port, p, p->ref, p->len));
    /* Put address in a separate pbuf and tack it onto the packet. */
    struct pbuf *sap =
        pbuf_alloc(PBUF_RAW, sizeof(union socket_address), PBUF_RAM);
    if (sap == NULL) {
        pbuf_free(p);
        return;
    }
    union socket_address *sa = (union socket_address *) sap->payload;
#if ((LWIP_VERSION_MAJOR << 8) | LWIP_VERSION_MINOR) >= 0x0105
    sa->sin.sin_addr.s_addr = ip_2_ip4(addr)->addr;
#else
    sa->sin.sin_addr.s_addr = addr->addr;
#endif
    sa->sin.sin_port = htons(port);
    /* Logic in the recv handler requires that there be exactly one data pbuf. */
    p = pbuf_coalesce(p, PBUF_RAW);
    pbuf_chain(sap, p);
    mgos_lock();
    mg_lwip_recv_common(nc, sap);
    mgos_unlock();
    (void)pcb;
}

static void mg_lwip_recv_common(struct mg_connection *nc, struct pbuf *p) {
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    if (cs->rx_chain == NULL) {
        cs->rx_chain = p;
    }
    else {
        pbuf_chain(cs->rx_chain, p);
    }
    if (!cs->recv_pending) {
        cs->recv_pending = 1;
        mg_lwip_post_signal(MG_SIG_RECV, nc);
    }
}

static int mg_lwip_if_udp_recv(struct mg_connection *nc, void *buf, size_t len,
    union socket_address *sa, size_t *sa_len) {
    /*
     * For UDP, RX chain consists of interleaved address and packet bufs:
     * Address pbuf followed by exactly one data pbuf (recv_cb took care of that).
     */
    int res = 0;
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    if (nc->sock == INVALID_SOCKET) return -1;
    mgos_lock();
    if (cs->rx_chain != NULL) {
        struct pbuf *ap = cs->rx_chain;
        struct pbuf *dp = ap->next;
        cs->rx_chain = pbuf_dechain(dp);
        res = MIN(dp->len, len);
        pbuf_copy_partial(dp, buf, res, 0);
        pbuf_free(dp);
        pbuf_copy_partial(ap, sa, MIN(*sa_len, ap->len), 0);
        pbuf_free(ap);
    }
    mgos_unlock();
    return res;
}

static void mg_lwip_if_connect_udp_tcpip(void *arg) {
    struct mg_connection *nc = (struct mg_connection *) arg;
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    struct udp_pcb *upcb = udp_new();
    cs->err = UDP_BIND(upcb, IP_ADDR_ANY, 0 /* any port */);
    DBG(("%p udp_bind %p = %d", nc, upcb, cs->err));
    if (cs->err == ERR_OK) {
        udp_recv(upcb, mg_lwip_udp_recv_cb, nc);
        cs->pcb.udp = upcb;
    }
    else {
        udp_remove(upcb);
    }
    mg_lwip_post_signal(MG_SIG_CONNECT_RESULT, nc);
}

void mg_lwip_if_connect_udp(struct mg_connection *nc) {
    mg_lwip_netif_run_on_tcpip(mg_lwip_if_connect_udp_tcpip, nc);
}

static void tcp_close_tcpip(void *arg) {
    tcp_close((struct tcp_pcb *) arg);
}

void mg_lwip_handle_accept(struct mg_connection *nc) {
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    if (cs->pcb.tcp == NULL) return;
    union socket_address sa;
    struct tcp_pcb *tpcb = cs->pcb.tcp;
    SET_ADDR(&sa, &tpcb->remote_ip);
    sa.sin.sin_port = htons(tpcb->remote_port);
    mg_if_accept_tcp_cb(nc, &sa, sizeof(sa.sin));
}

static err_t mg_lwip_accept_cb(void *arg, struct tcp_pcb *newtpcb, err_t err) {
    struct mg_connection *lc = (struct mg_connection *) arg, *nc;
    struct mg_lwip_conn_state *lcs, *cs;
    struct tcp_pcb_listen *lpcb;
    LOG(LL_DEBUG,
        ("%p conn %p from %s:%u", lc, newtpcb,
            IPADDR_NTOA(ipX_2_ip(&newtpcb->remote_ip)), newtpcb->remote_port));
    if (lc == NULL) {
        tcp_abort(newtpcb);
        return ERR_ABRT;
    }
    lcs = (struct mg_lwip_conn_state *) lc->sock;
    lpcb = (struct tcp_pcb_listen *) lcs->pcb.tcp;
#if TCP_LISTEN_BACKLOG
    tcp_accepted(lpcb);
#endif
    nc = mg_if_accept_new_conn(lc);
    if (nc == NULL) {
        tcp_abort(newtpcb);
        return ERR_ABRT;
    }
    cs = (struct mg_lwip_conn_state *) nc->sock;
    cs->lc = lc;
    cs->pcb.tcp = newtpcb;
    /* We need to set up callbacks before returning because data may start
     * arriving immediately. */
    tcp_arg(newtpcb, nc);
    tcp_err(newtpcb, mg_lwip_tcp_error_cb);
    tcp_sent(newtpcb, mg_lwip_tcp_sent_cb);
    tcp_recv(newtpcb, mg_lwip_tcp_recv_cb);
#if LWIP_TCP_KEEPALIVE
    mg_lwip_set_keepalive_params(nc, 60, 10, 6);
#endif
    mg_lwip_post_signal(MG_SIG_ACCEPT, nc);
    (void)err;
    (void)lpcb;
    return ERR_OK;
}

struct mg_lwip_if_listen_ctx {
    struct mg_connection *nc;
    union socket_address *sa;
    int ret;
};

static void mg_lwip_if_listen_tcp_tcpip(void *arg) {
    struct mg_lwip_if_listen_ctx *ctx = (struct mg_lwip_if_listen_ctx *) arg;
    struct mg_connection *nc = ctx->nc;
    union socket_address *sa = ctx->sa;
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    struct tcp_pcb *tpcb = TCP_NEW();
    ip_addr_t *ip = (ip_addr_t *)&sa->sin.sin_addr.s_addr;
    u16_t port = ntohs(sa->sin.sin_port);
    cs->err = TCP_BIND(tpcb, ip, port);
    DBG(("%p tcp_bind(%s:%u) = %d", nc, IPADDR_NTOA(ip), port, cs->err));
    if (cs->err != ERR_OK) {
        tcp_close(tpcb);
        ctx->ret = -1;
        return;
    }
    tcp_arg(tpcb, nc);
    tpcb = tcp_listen(tpcb);
    cs->pcb.tcp = tpcb;
    tcp_accept(tpcb, mg_lwip_accept_cb);
    ctx->ret = 0;
}

int mg_lwip_if_listen_tcp(struct mg_connection *nc, union socket_address *sa) {
    struct mg_lwip_if_listen_ctx ctx = { .nc = nc,.sa = sa };
    mg_lwip_netif_run_on_tcpip(mg_lwip_if_listen_tcp_tcpip, &ctx);
    return ctx.ret;
}

static void mg_lwip_if_listen_udp_tcpip(void *arg) {
    struct mg_lwip_if_listen_ctx *ctx = (struct mg_lwip_if_listen_ctx *) arg;
    struct mg_connection *nc = ctx->nc;
    union socket_address *sa = ctx->sa;
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    struct udp_pcb *upcb = udp_new();
    ip_addr_t *ip = (ip_addr_t *)&sa->sin.sin_addr.s_addr;
    u16_t port = ntohs(sa->sin.sin_port);
    cs->err = UDP_BIND(upcb, ip, port);
    DBG(("%p udb_bind(%s:%u) = %d", nc, IPADDR_NTOA(ip), port, cs->err));
    if (cs->err != ERR_OK) {
        udp_remove(upcb);
        ctx->ret = -1;
    }
    else {
        udp_recv(upcb, mg_lwip_udp_recv_cb, nc);
        cs->pcb.udp = upcb;
        ctx->ret = 0;
    }
}

int mg_lwip_if_listen_udp(struct mg_connection *nc, union socket_address *sa) {
    struct mg_lwip_if_listen_ctx ctx = { .nc = nc,.sa = sa };
    mg_lwip_netif_run_on_tcpip(mg_lwip_if_listen_udp_tcpip, &ctx);
    return ctx.ret;
}

struct mg_lwip_tcp_write_ctx {
    struct mg_connection *nc;
    const void *data;
    uint16_t len;
    int ret;
};

static void tcp_output_tcpip(void *arg) {
    tcp_output((struct tcp_pcb *) arg);
}

static void mg_lwip_tcp_write_tcpip(void *arg) {
    struct mg_lwip_tcp_write_ctx *ctx = (struct mg_lwip_tcp_write_ctx *) arg;
    struct mg_connection *nc = ctx->nc;
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    struct tcp_pcb *tpcb = cs->pcb.tcp;
    size_t len = MIN(tpcb->mss, MIN(ctx->len, tpcb->snd_buf));
    size_t unsent, unacked;
    if (len == 0) {
        DBG(("%p no buf avail %u %u %p %p", tpcb, tpcb->snd_buf, tpcb->snd_queuelen,
            tpcb->unsent, tpcb->unacked));
        mg_lwip_netif_run_on_tcpip(tcp_output_tcpip, tpcb);
        ctx->ret = 0;
        return;
    }
    unsent = (tpcb->unsent != NULL ? tpcb->unsent->len : 0);
    unacked = (tpcb->unacked != NULL ? tpcb->unacked->len : 0);
    /*
     * On ESP8266 we only allow one TCP segment in flight at any given time.
     * This may increase latency and reduce efficiency of tcp windowing,
     * but memory is scarce and precious on that platform so we do this to
     * reduce footprint.
     */
#if CS_PLATFORM == CS_P_ESP8266
    if (unacked > 0) {
        ctx->ret = 0;
        return;
    }
    len = MIN(len, (TCP_MSS - unsent));
#endif
    cs->err = tcp_write(tpcb, ctx->data, len, TCP_WRITE_FLAG_COPY);
    unsent = (tpcb->unsent != NULL ? tpcb->unsent->len : 0);
    unacked = (tpcb->unacked != NULL ? tpcb->unacked->len : 0);
    DBG(("%p tcp_write %u = %d, %u %u", tpcb, len, cs->err, unsent, unacked));
    if (cs->err != ERR_OK) {
        /*
         * We ignore ERR_MEM because memory will be freed up when the data is sent
         * and we'll retry.
         */
        ctx->ret = (cs->err == ERR_MEM ? 0 : -1);
        return;
    }
    ctx->ret = len;
    (void)unsent;
    (void)unacked;
}

int mg_lwip_if_tcp_send(struct mg_connection *nc, const void *buf, size_t len) {
    struct mg_lwip_tcp_write_ctx ctx = { .nc = nc,.data = buf,.len = len };
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    if (nc->sock == INVALID_SOCKET) return -1;
    struct tcp_pcb *tpcb = cs->pcb.tcp;
    if (tpcb == NULL) return -1;
    if (tpcb->snd_buf <= 0) return 0;
    mg_lwip_netif_run_on_tcpip(mg_lwip_tcp_write_tcpip, &ctx);
    return ctx.ret;
}

struct udp_sendto_ctx {
    struct udp_pcb *upcb;
    struct pbuf *p;
    ip_addr_t *ip;
    uint16_t port;
    int ret;
};

static void udp_sendto_tcpip(void *arg) {
    struct udp_sendto_ctx *ctx = (struct udp_sendto_ctx *) arg;
    ctx->ret = udp_sendto(ctx->upcb, ctx->p, ctx->ip, ctx->port);
}

static int mg_lwip_if_udp_send(struct mg_connection *nc, const void *data,
    size_t len) {
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    if (nc->sock == INVALID_SOCKET || cs->pcb.udp == NULL) return -1;
    struct udp_pcb *upcb = cs->pcb.udp;
    struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, len, PBUF_RAM);
#if defined(LWIP_IPV4) && LWIP_IPV4 && defined(LWIP_IPV6) && LWIP_IPV6
    ip_addr_t ip = { .u_addr.ip4.addr = nc->sa.sin.sin_addr.s_addr,.type = 0 };
#else
    ip_addr_t ip = { .addr = nc->sa.sin.sin_addr.s_addr };
#endif
    u16_t port = ntohs(nc->sa.sin.sin_port);
    if (p == NULL) return 0;
    memcpy(p->payload, data, len);
    struct udp_sendto_ctx ctx = { .upcb = upcb,.p = p,.ip = &ip,.port = port };
    mg_lwip_netif_run_on_tcpip(udp_sendto_tcpip, &ctx);
    cs->err = ctx.ret;
    pbuf_free(p);
    return (cs->err == ERR_OK ? (int)len : -2);
}

static int mg_lwip_if_can_send(struct mg_connection *nc,
    struct mg_lwip_conn_state *cs) {
    int can_send = 0;
    if (nc->send_mbuf.len > 0 || (nc->flags & MG_F_WANT_WRITE)) {
        /* We have stuff to send, but can we? */
        if (nc->flags & MG_F_UDP) {
            /* UDP is always ready for sending. */
            can_send = (cs->pcb.udp != NULL);
        }
        else {
            can_send = (cs->pcb.tcp != NULL && cs->pcb.tcp->snd_buf > 0);
            /* See comment above. */
#if CS_PLATFORM == CS_P_ESP8266
            if (cs->pcb.tcp->unacked != NULL) can_send = 0;
#endif
        }
    }
    return can_send;
}

struct tcp_recved_ctx {
    struct tcp_pcb *tpcb;
    size_t len;
};

void tcp_recved_tcpip(void *arg) {
    struct tcp_recved_ctx *ctx = (struct tcp_recved_ctx *) arg;
    if (ctx->tpcb != NULL) tcp_recved(ctx->tpcb, ctx->len);
}

static int mg_lwip_if_tcp_recv(struct mg_connection *nc, void *buf,
    size_t len) {
    int res = 0;
    char *bufp = buf;
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    if (nc->sock == INVALID_SOCKET) return -1;
    mgos_lock();
    while (cs->rx_chain != NULL && len > 0) {
        struct pbuf *seg = cs->rx_chain;
        size_t seg_len = (seg->len - cs->rx_offset);
        size_t copy_len = MIN(len, seg_len);

        pbuf_copy_partial(seg, bufp, copy_len, cs->rx_offset);
        len -= copy_len;
        res += copy_len;
        bufp += copy_len;
        cs->rx_offset += copy_len;
        if (cs->rx_offset == cs->rx_chain->len) {
            cs->rx_chain = pbuf_dechain(cs->rx_chain);
            pbuf_free(seg);
            cs->rx_offset = 0;
        }
    }
    mgos_unlock();
    if (res > 0) {
        struct tcp_recved_ctx ctx = { .tpcb = cs->pcb.tcp,.len = res };
        mg_lwip_netif_run_on_tcpip(tcp_recved_tcpip, &ctx);
    }
    return res;
}

int mg_lwip_if_create_conn(struct mg_connection *nc) {
    struct mg_lwip_conn_state *cs =
        (struct mg_lwip_conn_state *) MG_CALLOC(1, sizeof(*cs));
    if (cs == NULL) return 0;
    cs->nc = nc;
    nc->sock = (intptr_t)cs;
    return 1;
}

static void udp_remove_tcpip(void *arg) {
    udp_remove((struct udp_pcb *) arg);
}

void mg_lwip_if_destroy_conn(struct mg_connection *nc) {
    if (nc->sock == INVALID_SOCKET) return;
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    if (!(nc->flags & MG_F_UDP)) {
        struct tcp_pcb *tpcb = cs->pcb.tcp;
        if (tpcb != NULL) {
            tcp_arg(tpcb, NULL);
            DBG(("%p tcp_close %p", nc, tpcb));
            tcp_arg(tpcb, NULL);
            mg_lwip_netif_run_on_tcpip(tcp_close_tcpip, tpcb);
        }
        while (cs->rx_chain != NULL) {
            struct pbuf *seg = cs->rx_chain;
            cs->rx_chain = pbuf_dechain(cs->rx_chain);
            pbuf_free(seg);
        }
        memset(cs, 0, sizeof(*cs));
        MG_FREE(cs);
    }
    else if (nc->listener == NULL) {
        /* Only close outgoing UDP pcb or listeners. */
        struct udp_pcb *upcb = cs->pcb.udp;
        if (upcb != NULL) {
            DBG(("%p udp_remove %p", nc, upcb));
            mg_lwip_netif_run_on_tcpip(udp_remove_tcpip, upcb);
        }
        memset(cs, 0, sizeof(*cs));
        MG_FREE(cs);
    }
    nc->sock = INVALID_SOCKET;
}

void mg_lwip_if_get_conn_addr(struct mg_connection *nc, int remote,
    union socket_address *sa) {
    memset(sa, 0, sizeof(*sa));
    if (nc == NULL || nc->sock == INVALID_SOCKET) return;
    struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
    if (nc->flags & MG_F_UDP) {
        struct udp_pcb *upcb = cs->pcb.udp;
        if (remote) {
            memcpy(sa, &nc->sa, sizeof(*sa));
        }
        else if (upcb != NULL) {
            sa->sin.sin_port = htons(upcb->local_port);
            SET_ADDR(sa, &upcb->local_ip);
        }
    }
    else {
        struct tcp_pcb *tpcb = cs->pcb.tcp;
        if (remote) {
            memcpy(sa, &nc->sa, sizeof(*sa));
        }
        else if (tpcb != NULL) {
            sa->sin.sin_port = htons(tpcb->local_port);
            SET_ADDR(sa, &tpcb->local_ip);
        }
    }
}

void mg_lwip_if_sock_set(struct mg_connection *nc, sock_t sock) {
    nc->sock = sock;
}

/* clang-format off */
#define MG_LWIP_IFACE_VTABLE                                          \
  {                                                                   \
    mg_lwip_if_init,                                                  \
    mg_lwip_if_free,                                                  \
    mg_lwip_if_add_conn,                                              \
    mg_lwip_if_remove_conn,                                           \
    mg_lwip_if_poll,                                                  \
    mg_lwip_if_listen_tcp,                                            \
    mg_lwip_if_listen_udp,                                            \
    mg_lwip_if_connect_tcp,                                           \
    mg_lwip_if_connect_udp,                                           \
    mg_lwip_if_tcp_send,                                              \
    mg_lwip_if_udp_send,                                              \
    mg_lwip_if_tcp_recv,                                              \
    mg_lwip_if_udp_recv,                                              \
    mg_lwip_if_create_conn,                                           \
    mg_lwip_if_destroy_conn,                                          \
    mg_lwip_if_sock_set,                                              \
    mg_lwip_if_get_conn_addr,                                         \
  }
/* clang-format on */

const struct mg_iface_vtable mg_lwip_iface_vtable = MG_LWIP_IFACE_VTABLE;
#if MG_NET_IF == MG_NET_IF_LWIP_LOW_LEVEL
const struct mg_iface_vtable mg_default_iface_vtable = MG_LWIP_IFACE_VTABLE;
#endif

#endif /* MG_ENABLE_NET_IF_LWIP_LOW_LEVEL */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/lwip/mg_lwip_ev_mgr.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#if MG_NET_IF == MG_NET_IF_LWIP_LOW_LEVEL

#ifndef MG_SIG_QUEUE_LEN
#define MG_SIG_QUEUE_LEN 32
#endif

struct mg_ev_mgr_lwip_signal {
    int sig;
    struct mg_connection *nc;
};

struct mg_ev_mgr_lwip_data {
    struct mg_ev_mgr_lwip_signal sig_queue[MG_SIG_QUEUE_LEN];
    int sig_queue_len;
    int start_index;
};

void mg_lwip_post_signal(enum mg_sig_type sig, struct mg_connection *nc) {
    struct mg_ev_mgr_lwip_data *md =
        (struct mg_ev_mgr_lwip_data *) nc->iface->data;
    mgos_lock();
    if (md->sig_queue_len >= MG_SIG_QUEUE_LEN) {
        mgos_unlock();
        return;
    }
    int end_index = (md->start_index + md->sig_queue_len) % MG_SIG_QUEUE_LEN;
    md->sig_queue[end_index].sig = sig;
    md->sig_queue[end_index].nc = nc;
    md->sig_queue_len++;
    mg_lwip_mgr_schedule_poll(nc->mgr);
    mgos_unlock();
}

void mg_ev_mgr_lwip_process_signals(struct mg_mgr *mgr) {
    struct mg_ev_mgr_lwip_data *md =
        (struct mg_ev_mgr_lwip_data *) mgr->ifaces[MG_MAIN_IFACE]->data;
    while (md->sig_queue_len > 0) {
        mgos_lock();
        int i = md->start_index;
        int sig = md->sig_queue[i].sig;
        struct mg_connection *nc = md->sig_queue[i].nc;
        struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
        md->start_index = (i + 1) % MG_SIG_QUEUE_LEN;
        md->sig_queue_len--;
        mgos_unlock();
        if (nc->iface == NULL || nc->mgr == NULL) continue;
        switch (sig) {
        case MG_SIG_CONNECT_RESULT: {
            mg_if_connect_cb(nc, cs->err);
            break;
        }
        case MG_SIG_CLOSE_CONN: {
            mg_close_conn(nc);
            break;
        }
        case MG_SIG_RECV: {
            cs->recv_pending = 0;
            mg_if_can_recv_cb(nc);
            mbuf_trim(&nc->recv_mbuf);
            break;
        }
        case MG_SIG_TOMBSTONE: {
            break;
        }
        case MG_SIG_ACCEPT: {
            mg_lwip_handle_accept(nc);
            break;
        }
        }
    }
}

void mg_lwip_if_init(struct mg_iface *iface) {
    LOG(LL_INFO, ("Mongoose %s, LwIP %u.%u.%u", MG_VERSION, LWIP_VERSION_MAJOR,
        LWIP_VERSION_MINOR, LWIP_VERSION_REVISION));
    iface->data = MG_CALLOC(1, sizeof(struct mg_ev_mgr_lwip_data));
#if !NO_SYS && !LWIP_TCPIP_CORE_LOCKING
    sys_sem_new(&s_tcpip_call_lock_sem, 1);
    sys_sem_new(&s_tcpip_call_sync_sem, 0);
#endif
}

void mg_lwip_if_free(struct mg_iface *iface) {
    MG_FREE(iface->data);
    iface->data = NULL;
}

void mg_lwip_if_add_conn(struct mg_connection *nc) {
    (void)nc;
}

void mg_lwip_if_remove_conn(struct mg_connection *nc) {
    struct mg_ev_mgr_lwip_data *md =
        (struct mg_ev_mgr_lwip_data *) nc->iface->data;
    /* Walk the queue and null-out further signals for this conn. */
    for (int i = 0; i < MG_SIG_QUEUE_LEN; i++) {
        if (md->sig_queue[i].nc == nc) {
            md->sig_queue[i].sig = MG_SIG_TOMBSTONE;
        }
    }
}

time_t mg_lwip_if_poll(struct mg_iface *iface, int timeout_ms) {
    struct mg_mgr *mgr = iface->mgr;
    int n = 0;
    double now = mg_time();
    struct mg_connection *nc, *tmp;
    double min_timer = 0;
    int num_timers = 0;
#if 0
    DBG(("begin poll @%u", (unsigned int)(now * 1000)));
#endif
    mg_ev_mgr_lwip_process_signals(mgr);
    for (nc = mgr->active_connections; nc != NULL; nc = tmp) {
        struct mg_lwip_conn_state *cs = (struct mg_lwip_conn_state *) nc->sock;
        tmp = nc->next;
        n++;
        if (!mg_if_poll(nc, now)) continue;
        if (nc->sock != INVALID_SOCKET &&
            !(nc->flags & (MG_F_UDP | MG_F_LISTENING)) && cs->pcb.tcp != NULL &&
            cs->pcb.tcp->unsent != NULL) {
            mg_lwip_netif_run_on_tcpip(tcp_output_tcpip, cs->pcb.tcp);
        }
        if (nc->ev_timer_time > 0) {
            if (num_timers == 0 || nc->ev_timer_time < min_timer) {
                min_timer = nc->ev_timer_time;
            }
            num_timers++;
        }

        if (nc->sock != INVALID_SOCKET) {
            if (mg_lwip_if_can_send(nc, cs)) {
                mg_if_can_send_cb(nc);
                mbuf_trim(&nc->send_mbuf);
            }
            if (cs->rx_chain != NULL) {
                mg_if_can_recv_cb(nc);
            }
            else if (cs->draining_rx_chain) {
                /*
                 * If the connection is about to close, and rx_chain is finally empty,
                 * send the MG_SIG_CLOSE_CONN signal
                 */
                mg_lwip_post_signal(MG_SIG_CLOSE_CONN, nc);
            }
        }
    }
#if 0
    DBG(("end poll @%u, %d conns, %d timers (min %u), next in %d ms",
        (unsigned int)(now * 1000), n, num_timers,
        (unsigned int)(min_timer * 1000), timeout_ms));
#endif
    (void)timeout_ms;
    return now;
}

#endif /* MG_NET_IF == MG_NET_IF_LWIP_LOW_LEVEL */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/wince/wince_libc.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifdef WINCE

const char *strerror(int err) {
    /*
     * TODO(alashkin): there is no strerror on WinCE;
     * look for similar wce_xxxx function
     */
    static char buf[10];
    snprintf(buf, sizeof(buf), "%d", err);
    return buf;
}

int open(const char *filename, int oflag, int pmode) {
    /*
     * TODO(alashkin): mg_open function is not used in mongoose
     * but exists in documentation as utility function
     * Shall we delete it at all or implement for WinCE as well?
     */
    DebugBreak();
    return 0; /* for compiler */
}

int _wstati64(const wchar_t *path, cs_stat_t *st) {
    DWORD fa = GetFileAttributesW(path);
    if (fa == INVALID_FILE_ATTRIBUTES) {
        return -1;
    }
    memset(st, 0, sizeof(*st));
    if ((fa & FILE_ATTRIBUTE_DIRECTORY) == 0) {
        HANDLE h;
        FILETIME ftime;
        st->st_mode |= _S_IFREG;
        h = CreateFileW(path, GENERIC_READ, 0, NULL, OPEN_EXISTING,
            FILE_ATTRIBUTE_NORMAL, NULL);
        if (h == INVALID_HANDLE_VALUE) {
            return -1;
        }
        st->st_size = GetFileSize(h, NULL);
        GetFileTime(h, NULL, NULL, &ftime);
        st->st_mtime = (uint32_t)((((uint64_t)ftime.dwLowDateTime +
            ((uint64_t)ftime.dwHighDateTime << 32)) /
            10000000.0) -
            11644473600);
        CloseHandle(h);
    }
    else {
        st->st_mode |= _S_IFDIR;
    }
    return 0;
}

/* Windows CE doesn't have neither gmtime nor strftime */
static void mg_gmt_time_string(char *buf, size_t buf_len, time_t *t) {
    FILETIME ft;
    SYSTEMTIME systime;
    if (t != NULL) {
        uint64_t filetime = (*t + 11644473600) * 10000000;
        ft.dwLowDateTime = filetime & 0xFFFFFFFF;
        ft.dwHighDateTime = (filetime & 0xFFFFFFFF00000000) >> 32;
        FileTimeToSystemTime(&ft, &systime);
    }
    else {
        GetSystemTime(&systime);
    }
    /* There is no PRIu16 in WinCE SDK */
    snprintf(buf, buf_len, "%d.%d.%d %d:%d:%d GMT", (int)systime.wYear,
        (int)systime.wMonth, (int)systime.wDay, (int)systime.wHour,
        (int)systime.wMinute, (int)systime.wSecond);
}

#endif
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/pic32/pic32_net_if.h"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CS_COMMON_PLATFORMS_PIC32_NET_IF_H_
#define CS_COMMON_PLATFORMS_PIC32_NET_IF_H_

 /* Amalgamated: #include "mongoose/src/net_if.h" */

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#ifndef MG_ENABLE_NET_IF_PIC32
#define MG_ENABLE_NET_IF_PIC32 MG_NET_IF == MG_NET_IF_PIC32
#endif

    extern const struct mg_iface_vtable mg_pic32_iface_vtable;

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* CS_COMMON_PLATFORMS_PIC32_NET_IF_H_ */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/pic32/pic32_net_if.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#if MG_ENABLE_NET_IF_PIC32

int mg_pic32_if_create_conn(struct mg_connection *nc) {
    (void)nc;
    return 1;
}

void mg_pic32_if_recved(struct mg_connection *nc, size_t len) {
    (void)nc;
    (void)len;
}

void mg_pic32_if_add_conn(struct mg_connection *nc) {
    (void)nc;
}

void mg_pic32_if_init(struct mg_iface *iface) {
    (void)iface;
    (void)mg_get_errno(); /* Shutup compiler */
}

void mg_pic32_if_free(struct mg_iface *iface) {
    (void)iface;
}

void mg_pic32_if_remove_conn(struct mg_connection *nc) {
    (void)nc;
}

void mg_pic32_if_destroy_conn(struct mg_connection *nc) {
    if (nc->sock == INVALID_SOCKET) return;
    /* For UDP, only close outgoing sockets or listeners. */
    if (!(nc->flags & MG_F_UDP)) {
        /* Close TCP */
        TCPIP_TCP_Close((TCP_SOCKET)nc->sock);
    }
    else if (nc->listener == NULL) {
        /* Only close outgoing UDP or listeners. */
        TCPIP_UDP_Close((UDP_SOCKET)nc->sock);
    }

    nc->sock = INVALID_SOCKET;
}

int mg_pic32_if_listen_udp(struct mg_connection *nc, union socket_address *sa) {
    nc->sock = TCPIP_UDP_ServerOpen(
        sa->sin.sin_family == AF_INET ? IP_ADDRESS_TYPE_IPV4
        : IP_ADDRESS_TYPE_IPV6,
        ntohs(sa->sin.sin_port),
        sa->sin.sin_addr.s_addr == 0 ? 0 : (IP_MULTI_ADDRESS *)&sa->sin);
    if (nc->sock == INVALID_SOCKET) {
        return -1;
    }
    return 0;
}

void mg_pic32_if_udp_send(struct mg_connection *nc, const void *buf,
    size_t len) {
    mbuf_append(&nc->send_mbuf, buf, len);
}

void mg_pic32_if_tcp_send(struct mg_connection *nc, const void *buf,
    size_t len) {
    mbuf_append(&nc->send_mbuf, buf, len);
}

int mg_pic32_if_listen_tcp(struct mg_connection *nc, union socket_address *sa) {
    nc->sock = TCPIP_TCP_ServerOpen(
        sa->sin.sin_family == AF_INET ? IP_ADDRESS_TYPE_IPV4
        : IP_ADDRESS_TYPE_IPV6,
        ntohs(sa->sin.sin_port),
        sa->sin.sin_addr.s_addr == 0 ? 0 : (IP_MULTI_ADDRESS *)&sa->sin);
    memcpy(&nc->sa, sa, sizeof(*sa));
    if (nc->sock == INVALID_SOCKET) {
        return -1;
    }
    return 0;
}

static int mg_accept_conn(struct mg_connection *lc) {
    struct mg_connection *nc;
    TCP_SOCKET_INFO si;
    union socket_address sa;

    nc = mg_if_accept_new_conn(lc);

    if (nc == NULL) {
        return 0;
    }

    nc->sock = lc->sock;
    nc->flags &= ~MG_F_LISTENING;

    if (!TCPIP_TCP_SocketInfoGet((TCP_SOCKET)nc->sock, &si)) {
        return 0;
    }

    if (si.addressType == IP_ADDRESS_TYPE_IPV4) {
        sa.sin.sin_family = AF_INET;
        sa.sin.sin_port = htons(si.remotePort);
        sa.sin.sin_addr.s_addr = si.remoteIPaddress.v4Add.Val;
    }
    else {
        /* TODO(alashkin): do something with _potential_ IPv6 */
        memset(&sa, 0, sizeof(sa));
    }

    mg_if_accept_tcp_cb(nc, (union socket_address *) &sa, sizeof(sa));

    return mg_pic32_if_listen_tcp(lc, &lc->sa) >= 0;
}

char *inet_ntoa(struct in_addr in) {
    static char addr[17];
    snprintf(addr, sizeof(addr), "%d.%d.%d.%d", (int)in.S_un.S_un_b.s_b1,
        (int)in.S_un.S_un_b.s_b2, (int)in.S_un.S_un_b.s_b3,
        (int)in.S_un.S_un_b.s_b4);
    return addr;
}

static void mg_handle_send(struct mg_connection *nc) {
    uint16_t bytes_written = 0;
    if (nc->flags & MG_F_UDP) {
        if (!TCPIP_UDP_RemoteBind(
            (UDP_SOCKET)nc->sock,
            nc->sa.sin.sin_family == AF_INET ? IP_ADDRESS_TYPE_IPV4
            : IP_ADDRESS_TYPE_IPV6,
            ntohs(nc->sa.sin.sin_port), (IP_MULTI_ADDRESS *)&nc->sa.sin)) {
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
            return;
        }
        bytes_written = TCPIP_UDP_TxPutIsReady((UDP_SOCKET)nc->sock, 0);
        if (bytes_written >= nc->send_mbuf.len) {
            if (TCPIP_UDP_ArrayPut((UDP_SOCKET)nc->sock,
                (uint8_t *)nc->send_mbuf.buf,
                nc->send_mbuf.len) != nc->send_mbuf.len) {
                nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                bytes_written = 0;
            }
        }
    }
    else {
        bytes_written = TCPIP_TCP_FifoTxFreeGet((TCP_SOCKET)nc->sock);
        if (bytes_written != 0) {
            if (bytes_written > nc->send_mbuf.len) {
                bytes_written = nc->send_mbuf.len;
            }
            if (TCPIP_TCP_ArrayPut((TCP_SOCKET)nc->sock,
                (uint8_t *)nc->send_mbuf.buf,
                bytes_written) != bytes_written) {
                nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                bytes_written = 0;
            }
        }
    }

    mg_if_sent_cb(nc, bytes_written);
}

static void mg_handle_recv(struct mg_connection *nc) {
    uint16_t bytes_read = 0;
    uint8_t *buf = NULL;
    if (nc->flags & MG_F_UDP) {
        bytes_read = TCPIP_UDP_GetIsReady((UDP_SOCKET)nc->sock);
        if (bytes_read != 0 &&
            (nc->recv_mbuf_limit == -1 ||
                nc->recv_mbuf.len + bytes_read < nc->recv_mbuf_limit)) {
            buf = (uint8_t *)MG_MALLOC(bytes_read);
            if (TCPIP_UDP_ArrayGet((UDP_SOCKET)nc->sock, buf, bytes_read) !=
                bytes_read) {
                nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                bytes_read = 0;
                MG_FREE(buf);
            }
        }
    }
    else {
        bytes_read = TCPIP_TCP_GetIsReady((TCP_SOCKET)nc->sock);
        if (bytes_read != 0) {
            if (nc->recv_mbuf_limit != -1 &&
                nc->recv_mbuf_limit - nc->recv_mbuf.len > bytes_read) {
                bytes_read = nc->recv_mbuf_limit - nc->recv_mbuf.len;
            }
            buf = (uint8_t *)MG_MALLOC(bytes_read);
            if (TCPIP_TCP_ArrayGet((TCP_SOCKET)nc->sock, buf, bytes_read) !=
                bytes_read) {
                nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                MG_FREE(buf);
                bytes_read = 0;
            }
        }
    }

    if (bytes_read != 0) {
        mg_if_recv_tcp_cb(nc, buf, bytes_read, 1 /* own */);
    }
}

time_t mg_pic32_if_poll(struct mg_iface *iface, int timeout_ms) {
    struct mg_mgr *mgr = iface->mgr;
    double now = mg_time();
    struct mg_connection *nc, *tmp;

    for (nc = mgr->active_connections; nc != NULL; nc = tmp) {
        tmp = nc->next;

        if (nc->flags & MG_F_CONNECTING) {
            /* processing connections */
            if (nc->flags & MG_F_UDP ||
                TCPIP_TCP_IsConnected((TCP_SOCKET)nc->sock)) {
                mg_if_connect_cb(nc, 0);
            }
        }
        else if (nc->flags & MG_F_LISTENING) {
            if (TCPIP_TCP_IsConnected((TCP_SOCKET)nc->sock)) {
                /* accept new connections */
                mg_accept_conn(nc);
            }
        }
        else {
            if (nc->send_mbuf.len != 0) {
                mg_handle_send(nc);
            }

            if (nc->recv_mbuf_limit == -1 ||
                nc->recv_mbuf.len < nc->recv_mbuf_limit) {
                mg_handle_recv(nc);
            }
        }
    }

    for (nc = mgr->active_connections; nc != NULL; nc = tmp) {
        tmp = nc->next;
        if ((nc->flags & MG_F_CLOSE_IMMEDIATELY) ||
            (nc->send_mbuf.len == 0 && (nc->flags & MG_F_SEND_AND_CLOSE))) {
            mg_close_conn(nc);
        }
    }

    return now;
}

void mg_pic32_if_sock_set(struct mg_connection *nc, sock_t sock) {
    nc->sock = sock;
}

void mg_pic32_if_get_conn_addr(struct mg_connection *nc, int remote,
    union socket_address *sa) {
    /* TODO(alaskin): not implemented yet */
}

void mg_pic32_if_connect_tcp(struct mg_connection *nc,
    const union socket_address *sa) {
    nc->sock = TCPIP_TCP_ClientOpen(
        sa->sin.sin_family == AF_INET ? IP_ADDRESS_TYPE_IPV4
        : IP_ADDRESS_TYPE_IPV6,
        ntohs(sa->sin.sin_port), (IP_MULTI_ADDRESS *)&sa->sin);
    nc->err = (nc->sock == INVALID_SOCKET) ? -1 : 0;
}

void mg_pic32_if_connect_udp(struct mg_connection *nc) {
    nc->sock = TCPIP_UDP_ClientOpen(IP_ADDRESS_TYPE_ANY, 0, NULL);
    nc->err = (nc->sock == INVALID_SOCKET) ? -1 : 0;
}

/* clang-format off */
#define MG_PIC32_IFACE_VTABLE                                   \
  {                                                             \
    mg_pic32_if_init,                                           \
    mg_pic32_if_free,                                           \
    mg_pic32_if_add_conn,                                       \
    mg_pic32_if_remove_conn,                                    \
    mg_pic32_if_poll,                                           \
    mg_pic32_if_listen_tcp,                                     \
    mg_pic32_if_listen_udp,                                     \
    mg_pic32_if_connect_tcp,                                    \
    mg_pic32_if_connect_udp,                                    \
    mg_pic32_if_tcp_send,                                       \
    mg_pic32_if_udp_send,                                       \
    mg_pic32_if_recved,                                         \
    mg_pic32_if_create_conn,                                    \
    mg_pic32_if_destroy_conn,                                   \
    mg_pic32_if_sock_set,                                       \
    mg_pic32_if_get_conn_addr,                                  \
  }
/* clang-format on */

const struct mg_iface_vtable mg_pic32_iface_vtable = MG_PIC32_IFACE_VTABLE;
#if MG_NET_IF == MG_NET_IF_PIC32
const struct mg_iface_vtable mg_default_iface_vtable = MG_PIC32_IFACE_VTABLE;
#endif

#endif /* MG_ENABLE_NET_IF_PIC32 */
#ifdef MG_MODULE_LINES
#line 1 "common/platforms/windows/windows_direct.c"
#endif
/*
 * Copyright (c) 2014-2018 Cesanta Software Limited
 * All rights reserved
 *
 * Licensed under the Apache License, Version 2.0 (the ""License"");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an ""AS IS"" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifdef _WIN32

int rmdir(const char *dirname) {
    return _rmdir(dirname);
}

unsigned int sleep(unsigned int seconds) {
    Sleep(seconds * 1000);
    return 0;
}

#endif /* _WIN32 */